MP Board Class 7th Sanskrit Solutions सुरभिः

MP Board Class 7th Sanskrit Solutions Guide Pdf Free Download संस्कृत सुरभिः are part of MP Board Class 7th Solutions. Here we have given Madhya Pradesh Syllabus MP Board Surbhi Sanskrit Book Class 7 Solutions Pdf.

MP Board Class 7th Sanskrit Book Solutions Surbhi

Here we have given MP Board Surbhi Samanya Sanskrit Book Class 7 Solutions Kaksha 7 (संस्कृत सामान्य सुरभिः कक्षा 7).

Surbhi Sanskrit Book Class 7 Solutions

पाठ का हिन्दी अनुवाद, शब्दार्थ एवं अभ्यास

MP Board Class 7th Sanskrit Model Question Paper (आदर्श प्रश्नपत्रम्)

We hope the given MP Board Class 7 Sanskrit Solutions Guide Pdf Free Download संस्कृत will help you. If you have any query regarding Madhya Pradesh Syllabus MP Board Class 7 Sanskrit Book Solutions Surbhi Pdf, drop a comment below and we will get back to you at the earliest.

MP Board Class 12th Maths Solutions गणित

MP Board Class 12th Maths Solutions Guide Pdf Free Download गणित in both Hindi Medium and English Medium are part of MP Board Class 12th Solutions. Here we have given NCERT Solutions of Madhya Pradesh Syllabus MP Board Class 12 Maths Book Solutions Ganit Pdf.

Students can also download MP Board 12th Model Papers to help you to revise the complete Syllabus and score more marks in your examinations.

MP Board Class 12th Maths Book Solutions in Hindi Medium

MP Board Class 12th Maths Chapter 1 संबंध एवं फलन

MP Board Class 12th Maths Chapter 2 प्रतिलोम त्रिकोणमितीय फलन

MP Board Class 12th Maths Chapter 3 आव्यूह

MP Board Class 12th Maths Chapter 4 सारणिक

MP Board Class 12th Maths Chapter 5 सांतत्य तथा अवकलनीयता

MP Board Class 12th Maths Chapter 6 अवकलज के अनुप्रयोग

MP Board Class 12th Maths Chapter 7 समाकलन

MP Board Class 12th Maths Chapter 8 समाकलनों के अनुप्रयोग

MP Board Class 12th Maths Chapter 9 अवकल समीकरण

MP Board Class 12th Maths Chapter 10 सदिश बीजगणित

MP Board Class 12th Maths Chapter 11 त्रि-विमीय ज्यामिति

MP Board Class 12th Maths Chapter 12 रैखिक प्रोग्रामन

MP Board Class 12th Maths Chapter 13 प्रायिकता

MP Board Class 12th Maths Book Solutions in English Medium

MP Board Class 12th Maths Chapter 1 Relations and Functions

  • Chapter 1 Relations and Functions Ex 1.1
  • Chapter 1 Relations and Functions Ex 1.2
  • Chapter 1 Relations and Functions Ex 1.3
  • Chapter 1 Relations and Functions Ex 1.4
  • Chapter 1 Relations and Functions Miscellaneous Exercise

MP Board Class 12th Maths Chapter 2 Inverse Trigonometric Functions

  • Chapter 2 Inverse Trigonometric Functions Ex 2.1
  • Chapter 2 Inverse Trigonometric Functions Ex 2.2
  • Chapter 2 Inverse Trigonometric Functions Miscellaneous Exercise

MP Board Class 12th Maths Chapter 3 Matrices

  • Chapter 3 Matrices Ex 3.1
  • Chapter 3 Matrices Ex 3.2
  • Chapter 3 Matrices Ex 3.3
  • Chapter 3 Matrices Ex 3.4
  • Chapter 3 Matrices Miscellaneous Exercise

MP Board Class 12th Maths Chapter 4 Determinants

  • Chapter 4 Determinants Ex 4.1
  • Chapter 4 Determinants Ex 4.2
  • Chapter 4 Determinants Ex 4.3
  • Chapter 4 Determinants Ex 4.4
  • Chapter 4 Determinants Ex 4.5
  • Chapter 4 Determinants Ex 4.6
  • Chapter 4 Determinants Miscellaneous Exercise

MP Board Class 12th Maths Chapter 5 Continuity and Differentiability

  • Chapter 5 Continuity and Differentiability Ex 5.1
  • Chapter 5 Continuity and Differentiability Ex 5.2
  • Chapter 5 Continuity and Differentiability Ex 5.3
  • Chapter 5 Continuity and Differentiability Ex 5.4
  • Chapter 5 Continuity and Differentiability Ex 5.5
  • Chapter 5 Continuity and Differentiability Ex 5.6
  • Chapter 5 Continuity and Differentiability Ex 5.7
  • Chapter 5 Continuity and Differentiability Ex 5.8
  • Chapter 5 Continuity and Differentiability Miscellaneous Exercise

MP Board Class 12th Maths Chapter 6 Application of Derivatives

  • Chapter 6 Application of Derivatives Ex 6.1
  • Chapter 6 Application of Derivatives Ex 6.2
  • Chapter 6 Application of Derivatives Ex 6.3
  • Chapter 6 Application of Derivatives Ex 6.4
  • Chapter 6 Application of Derivatives Ex 6.5
  • Chapter 6 Application of Derivatives Miscellaneous Exercise

MP Board Class 12th Maths Chapter 7 Integrals

  • Chapter 7 Integrals Ex 7.1
  • Chapter 7 Integrals Ex 7.2
  • Chapter 7 Integrals Ex 7.3
  • Chapter 7 Integrals Ex 7.4
  • Chapter 7 Integrals Ex 7.5
  • Chapter 7 Integrals Ex 7.6
  • Chapter 7 Integrals Ex 7.7
  • Chapter 7 Integrals Ex 7.8
  • Chapter 7 Integrals Ex 7.9
  • Chapter 7 Integrals Ex 7.10
  • Chapter 7 Integrals Ex 7.11
  • Chapter 7 Integrals Miscellaneous Exercise

MP Board Class 12th Maths Chapter 8 Application of Integrals

  • Chapter 8 Application of Integrals Ex 8.1
  • Chapter 8 Application of Integrals Ex 8.2
  • Chapter 8 Application of Integrals Miscellaneous Exercise

MP Board Class 12th Maths Chapter 9 Differential Equations

  • Chapter 9 Differential Equations Ex 9.1
  • Chapter 9 Differential Equations Ex 9.2
  • Chapter 9 Differential Equations Ex 9.3
  • Chapter 9 Differential Equations Ex 9.4
  • Chapter 9 Differential Equations Ex 9.5
  • Chapter 9 Differential Equations Ex 9.6
  • Chapter 9 Differential Equations Miscellaneous Exercise

MP Board Class 12th Maths Chapter 10 Vector Algebra

  • Chapter 10 Vector Algebra Ex 10.1
  • Chapter 10 Vector Algebra Ex 10.2
  • Chapter 10 Vector Algebra Ex 10.3
  • Chapter 10 Vector Algebra Ex 10.4
  • Chapter 10 Vector Algebra Miscellaneous Exercise

MP Board Class 12th Maths Chapter 11 Three Dimensional Geometry

  • Chapter 11 Three Dimensional Geometry Ex 11.1
  • Chapter 11 Three Dimensional Geometry Ex 11.2
  • Chapter 11 Three Dimensional Geometry Ex 11.3
  • Chapter 11 Three Dimensional Geometry Miscellaneous Exercise

MP Board Class 12th Maths Chapter 12 Linear Programming

  • Chapter 12 Linear Programming Ex 12.1
  • Chapter 12 Linear Programming Ex 12.2
  • Chapter 12 Linear Programming Miscellaneous Exercise

MP Board Class 12th Maths Chapter 13 Probability

  • Chapter 13 Probability Ex 13.1
  • Chapter 13 Probability Ex 13.2
  • Chapter 13 Probability Ex 13.3
  • Chapter 13 Probability Ex 13.4
  • Chapter 13 Probability Ex 13.5
  • Chapter 13 Probability Miscellaneous Exercise

MP Board Class 12th Maths Syllabus and Marking Scheme

Latest Syllabus and Marks Distribution Maths Class XII for the academic year 2019 – 2020 Year Examination.

Maths
Class XII

Time : 3 Hours.
Maximum Marks: 100

Unit Wise Division of Marks

Unit Topics Periods Marks
I. Relations and Functions 30 10
II. Algebra 50 13
III. Calculus 80 44
IV. Vectors and Three-dimensional Geometry 30 17
V. Linear Programming 20 06
VI. Probability ‘ 30 10
Total 240 100

Unit I: Relations and Functions

1. Relations and Functions
Types of relations: reflexive, symmetric, transitive and equivalence relations. One to one and onto functions, composite functions, inverse of a function. Binary operations.

2. Inverse Trigonometric Functions
Definition, range, domain, principal value branch. Graphs of inverse trigonometric functions. Elementary properties of inverse trigonometric functions.

Unit II: Algebra

3. Matrices
Concept, notation, order, equality, types of matrices, zero and identity matrix, transpose of a matrix, symmetric and skew symmetric matrices. Operation on matrices: Addition and multiplication and multiplication with a scalar. Simple properties of addition, multiplication and scalar multiplication. Noncommutativity of multiplication of matrices and existence of non-zero matrices whose product is the zero matrix (restrict to square matrices of order 2). Concept of elementary row and column operations. Invertible matrices and proof of the uniqueness of inverse, if it exists; (Here all matrices will have real entries).

4. Determinants
Determinant of a square matrix (up to 3 x 3 matrices), properties of determinants, minors, co-factors and applications of determinants in finding the area of a triangle. Adjoint and inverse of a square matrix. Consistency, inconsistency and number of solutions of system of linear equations by examples, solving system of linear equations in two or three variables (having unique solution) using inverse of a matrix.

Unit III: Calculus

5. Continuity and Differentiability
Continuity and differentiability, derivative of composite functions, chain rule, derivatives of inverse trigonometric functions, derivative of implicit functions. Concept of exponential and logarithmic functions.
Derivatives of logarithmic and exponential functions. Logarithmic differentiation, derivative of functions expressed in parametric forms. Second order derivatives. Rolle’s and Lagrange’s Mean Value Theorems (without proof) and their geometric interpretation.

6. Applications of Derivatives
Applications of derivatives: rate of change of bodies, increasing/decreasing functions, tangents and normals, use of derivatives in approximation, maxima and minima (first derivative test motivated geometrically and second derivative test given as a provable tool). Simple problems (that illustrate basic principles and understanding of the subject as well as real-life situations).

7. Integrals
Integration as inverse process of differentiation.Integration of a variety of functions by substitution, by partial fractions and by parts, Evaluation of simple integrals of the following types and problems based on them.
Definite integrals as a limit of a sum, Fundamental Theorem of Calculus (without proof). Basic properties of definite integrals and evaluation of definite integrals.

8. Applications of the Integrals
Applications in finding the area under simple curves, especially lines, circles/parabolas/ellipses (in standard form only), Area between any of the two above said curves (the region should be clearly identifiable).

9. Differential Equations
Definition, order and degree, general and particular solutions of a differential equation.Formation of differential equation whose general solution is given. Solution of differential equations by method of separation of variables solutions of homogeneous differential equations of first order and first degree. Solutions of linear differential equation of the type:
dy/dx + py = q, where p and q are functions of x or constants.
dx/dy + px = q, where p and q are functions of y or constants.

Unit IV: Vectors and Three-Dimensional Geometry

10. Vectors
Vectors and scalars, magnitude and direction of a vector.Direction cosines and direction ratios of a vector. Types of vectors (equal, unit, zero, parallel and collinear vectors), position vector of a point, negative of a vector, components of a vector, addition of vectors, multiplication of a vector by a scalar, position vector of a point dividing a line segment in a given ratio. Definition, Geometrical Interpretation, properties and application of scalar (dot) product of vectors, vector (cross) product of vectors, scalar triple product of vectors.

11. Three – dimensional Geometry
Direction cosines and direction ratios of a line joining two points.Cartesian equation and vector equation of a line, coplanar and skew lines, shortest distance between two lines.Cartesian and vector equation of a plane. Angle between (i) two lines, (ii) two planes, (iii) a line and a plane. Distance of a point from a plane.

Unit V: Linear Programming

12. Linear Programming
Introduction, related terminology such as constraints, objective function, optimization, different types of linear programming (L.P.) problems, mathematical formulation of L.P. problems, graphical method of solution for problems in two variables, feasible and infeasible regions (bounded and unbounded), feasible and infeasible solutions, optimal feasible solutions (up to three non-trivial constraints).

Unit VI: Probability

13. Probability
Conditional probability, multiplication theorem on probability. independent events, total probability, Baye’s theorem, Random variable and its probability distribution, mean and variance of random variable. Repeated independent (Bernoulli) trials and Binomial distribution.

We hope the given MP Board Class 12th Maths Solutions Guide Pdf Free Download गणित in both Hindi Medium and English Medium will help you. If you have any queries regarding NCERT Madhya Pradesh Syllabus MP Board Class 12 Maths Book Solutions Ganit Pdf, drop a comment below and we will get back to you at the earliest.

MP Board Class 12th Chemistry Solutions रसायन विज्ञान

MP Board Class 12th Chemistry Solutions Guide Pdf Free Download रसायन विज्ञान in both Hindi Medium and English Medium are part of MP Board Class 12th Solutions. Here we have given Madhya Pradesh Syllabus NCERT Solutions for Class 12 Chemistry Book Solutions Rasayan Vigyan Pdf.

Students can also download MP Board 12th Model Papers to help you to revise the complete Syllabus and score more marks in your examinations.

MP Board Class 12th Chemistry Book Solutions in Hindi Medium

MP Board Class 12th Chemistry Book Solutions in English Medium

MP Board Class 12th Chemistry Syllabus and Marking Scheme

Latest Syllabus and Marks Distribution Chemistry Class XII for the academic year 2019 – 2020 Year Examination.

Chemistry
Class XII

Time : 3 Hours.
Maximum Marks: 70

Unit Wise Division of Marks

MP Board Class 12th Chemistry Syllabus and Marking Scheme

MP Board Class 12th Chemistry Syllabus and Marking Scheme

1. Solid State
Classification of solids based on different binding forces : Molecular, ionic, covalent and metallic solids, amorphous and crystalline solids (elementary idea). Unit cell in two-dimensional and three-dimensional lattices, calculation of density of unit cell, packing in solids, packing efficiency, voids, number of atoms per unit cell in a cubic unit cell, point defects, electrical and magnetic properties. Band theory of metals, conductors, semiconductors and insulators and n and p type semiconductors.

2. Solutions
Types of solutions, expression of concentration of solutions of solids in liquids, solubility of gases in liquids, solid solutions, colligative properties : Relative lowering of vapour pressure, Raoult’s law, elevation in boiling point, depression in freezing point, osmotic pressure, determination of molecular masses using colligative properties, abnormal molecular mass, van’t Hoff factor.

3. Electrochemistry
Redox reactions, conductance in electrolytic solutions, specific and molar con-ductivity, variations of conductivity with concentration, Kohlrausch’s law, elec-trolysis and law of electrolysis (elementary idea), dry cell- electrolytic cells and Galvanic cells; lead accumulator, EMF of a cell, standard electrode potential, Nemst equation and its application to chemical cells, Relation between Gibbs energy change and EMF of a cell, fuel cells, corrosion.

4. Chemical Kinetics
Rate of a reaction (Average and instantaneous), factors affecting rate of reaction : concentration, temperature, catalyst; order and molecularity of a reaction, rate law and specific rate constant, integrated rate equations and half-life (only for zero and first order reactions); concept of collision theory (elementary idea, no mathematical treatment). Activation energy, Arrhenius equation. Surface Chemistry

5. Adsorption : Physisorption and chemisorption, factors affecting adsorption of gases on solids.
Catalysis: Homogeneous and heterogeneous, activity and selectivity; enzyme catalysis.
Colloidal state : Distinction between true solutions, colloids and suspension; lyophilic, lyophobic, multimolecular and macromolecular colloids; properties of colloids; Tyndall effect, Brownian movement, electrophoresis, coagulation. Emulsion : Types of emulsions.

6. General Principles and Processes of Isolation of Elements
Principle and methods of extraction; concentration, oxidation, reduction, elec-trolytic method and refining, occurrence and principles of extraction of aluminium, copper, zinc and iron.

7. p-block Elements
Group-15 elements : General indroduction, electronic configuration, occurrence, oxidation states, trends in physical and chemical properties; Nitrogen : Preparation, properties and uses; compounds of nitrogen, preparation and properties of ammonia and nitric acid, oxides of nitrogen (structure only); Phosphorus : Allotropic forms; compounds of phosphorus preparation and properties of phosphine, halides (PC13, PC15) and oxo-acids (elementary idea only).
Group-16 elements : General introduction, electronic configuration, oxidation states, occurrence, trends in physical and chemical properties; Dioxygen; preparation, properties and uses; classification of oxides; ozone, Sulphur: allotropic forms; compounds of sulphur; preparation, properties and uses of sulphur dioxide; sulphuric acid, industrial process of manufacture, properties and uses, oxo-acids of sulphur (structures only).
Group-17 elements : General introduction, electronic configuration, oxidation states, occurrence, trends in physical and chemical properties; compounds of halogens; preparation, properties and uses of chlorine, hydrochloric acid and interhalogen compounds, oxo-acids of halogens (structures only). Group-18 elements : General introduction, electronic configuration, occurrence, trends in physical ahd chemical properties, uses.

8. d- and f-block Elements
General introduction, electronic configuration, occurrence and characteristics of transition metals, general trends in properties of the first row transition metals : metallic character, ionization enthalpy, oxidation states, ionic radii, colour, catalytic property, magnetic properties, interstitial compounds, alloy formation, preparation and properties of K2Cr207 and KMn04.
Lanthanoids : Electronic configuration, oxidation states, chemical reactivity and lanthanoid contraction and its consequences.
Actinoids : Electronic configuration, oxidation states and comparison with lanthanoids.

9. Co-ordination Compounds
Co-ordination compounds : Introduction, ligands, co-ordination number, colour, magnetic properties and shapes. IUPAC nomenclature of mononuclear co-ordination compounds. Bonding; Werner’s theory, VBT and CFT structure and stereo-isomerism, importance of co-ordination compounds (in qualitative inclusion, extraction of metals and biological system).

10. Haloalkanes and Haloarenes
Haloalkanes : Nomenclature, nature of C—X bond, physical and chemical properties, mechanism of substitution reactions, optical rotation.
Haloarenes : Nature of C—X bond, substitution reactions (Directive influence of halogen in monosubstituted compounds only). Uses and environmental effects of dichloromethane, trichloromethane, tetrachloromethane, iodoform, freons, DDT.

11. Alcohols, Phenols and Ethers
Alcohols: Nomenclature, methods of preparation, physical and chemical prop-erties of (primary alcohols only); identification of primary, secondary and tertiary alcohols; mechanism of dehydration, uses with special reference to methanol and ethanol.
Phenols : Nomenclature; methods of preparation, physical and chemical prop-erties, acidic nature of phenol, electrophilic substitution reactions, uses of phenols.
Ethers : Nomenclature; methods of preparation, physical and chemical properties, uses.

12. Aldehydes, Ketones and Carboxylic Acids
Aldehydes and Ketones : Nomenclature, nature of carbonyl group, methods of preparation, physical and chemical properties, mechanism of nucleophilic ad-dition, reactivity of alpha hydrogen in aldehydes; uses.
Carboxylic acids: Nomenclature, acidic nature, methods of preparation, physical and chemical properties; uses.

13. Organic Compounds Containing Nitrogen.
Amines: Nomenclature, classification, structure, methods of preparation, physical and chemical properties, uses, identification of primary, secondary and tertiary amines.
Cyanides and isocyanides : will be mentioned at relevant places in context. Diazonium salts: Preparation, chemical reactions and importance in synthetic organic chemistry.

14. Bio-molecules
Carbohydrates : Classification (aldoses and ketoses), monosaccharides (glucose and fructose), D-L configuration, oligosaccharides (sucrose, lactose, maltose), polysaccharides (starch, cellulose, glycogen); importance.
Proteins : Elementary idea of -amino acids, peptide bond, polypeptides, proteins, structure of proteins : primary, secondary, tertiary and quaternary structures (qualitative idea only), denaturation of proteins, enzymes. Hormones : elementary idea excluding structure.
Vitamins : Classification and functions.
Nucleic acids : DNA and RNA.

15. Polymers
Classification : Natural and synthetic, methods of polymerization (addition and condensation), copolymerization, some important polymers : Natural and synthetic like polythene, nylon, polyesters, bakelite, rubber. Biodegradable and non-biodegradable polymers.

16. Chemistry in Everyday Life
Chemicals in medjcines : Analgesics, tranquilizers, antiseptics, disinfectants, antimicrobials, antifertility drugs, antibiotics, antacids, antihistamines. Chemicals in food : Preservatives, artificial sweetening agents, elementaiy idea of antioxidants.
Cleansing agents : Soaps and detergents, cleansing action.

We hope the given MP Board Class 12th Chemistry Solutions Guide Pdf Free Download रसायन विज्ञान in both Hindi Medium and English Medium will help you. If you have any query regarding Madhya Pradesh Syllabus MP Board Class 12 Chemistry Book Solutions Rasayan Vigyan Pdf, drop a comment below and we will get back to you at the earliest.

MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry

MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry

Electrochemistry NCERT Intext Exercises

Electrochemistry Class 12 NCERT Solutions help to score more marks.

Question 1.
How would you determine the standard electrode potential of the system Mg2+ | Mg ?
Answer:
The standard electrode potential of the system Mg2+/ Mg can be determined as explained below. Prepare Mg2+/ Mg system by dipping Mg rod in a solution of Mg2+ ions and connect it to standard hydrogen electrode.
Mg | Mg2+ || H+(aq) | H2(g); Pt
When magnesium is connected with SHE, oxidation takes place at the Mg electrode. Hence, the potential of the magnesium electrode is taken as – ve The emf of the cell, determined potentiometrically, is equal to the potential of the magnesium electrode because the potential of SHE is taken as zero.

Question 2.
Can you store copper sulphate solutions in a zinc pot?
Answer:
No, it is not possible. The E° values of the copper and zinc electrodes are as follows :
Zn2+(aq) + 2e– → Zn(s) ; E° = – 0·76 V
Cu2+(aq) + 2e– → Cu(s) ; E° = + 0·34 V
This shows that zinc is a stronger reducing agent than copper. It will lose electrons to Cu2+ ions and a redox reaction will immediately set in.
Zn(s) + Cu2+ (aq) → Zn2+(aq) + Cu(s)
Thus, copper sulphate solution cannot be stored in zinc pot.

Question 3.
Consult the table of standard electrode potentials and suggest three substances that can oxidise ferrous ions under suitable conditions.
Answer:
Substances having higher E° values than Fe2+ ions can oxidise ferrous ions. Thus, Ag+, Hg2+, Br2, Cl2, F2 etc. can oxidise Fe2+ ions to Fe3+ ions.

Question 4.
Calculate the potential of the hydrogen electrode in contact with a solution whose pH is 10.
Solution:
For hydrogen electrode, H+ + e– → 1/2H2
Applying Nernst equation,
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 2

Question 5.
Calculate the emf of the cell in which the following reaction takes place :
Ni(s) + 2Ag+ (0.002 M) → Ni2+ (0.160 M) + 2Ag(s) Given that Ecell = 1.05 V.
Solution:
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 3

Question 6.
The cell in which the following reactions occurs :
2Fe3+(aq) + 2I(aq) → 2Fe2+(aq) + I2(s) has Ecell = 0-236 V at 298 K.
Calculate the standard Gibbs energy and the equilibrium constant of the cell reaction.
Solution:
The two half reactions are :
2Fe3+ + 2e → 2Fe2+ and 2I → I2 + 2e
For the above reaction, n = 2
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 4

Question 7.
Why does the conductivity of a solution decrease with dilution?
Answer:
The number of ions per unit volume that carry the current in a solution decreases on dilution. Therefore the conductivity of a solution decreases with dilution.

Question 8.
Suggest a way to determine the \(\wedge_{m}^{0}\) value of water.
Answer:
Conductance of weak electrolytes can be determined by kohlraush’s law. Thus, molar conductance of water of infinite dilution can be determined by the molar conductances of NaOH, HCl and NaCl at infinite dilution.
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 5

Question 9.
The molar conductivity of 0.025 mol L-1 methanoic acid is 46.1 S cm2 mol-1 Calculate its degree of dissociation and dissociation constant Given \(\lambda_{\left(\mathbf{H}^{+}\right)}^{\circ}\) = 349.6 S cm2 mol-1 and \(\lambda_{\left(\mathrm{H} \mathrm{COO}^{-}\right)}^{\circ}\) = 54.6 S cm2 mol.
Solution:
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 6

Question 10.
If a current of 0.5 ampere flows through a metallic wire for 2 hours, then how many electrons would flow through the wire ?
Solution:
Q (coulomb) = 1 (ampere) × t (sec)
Q = 0.5 ampere × 2 × 60 × 60
= 3600 C
A flow of IF, i.e. 96500 C is equivalent to flow of 1 mole of electrons
i. e., = 6.023 × 1023 electrons
3600 C is equivalent to flow of electrons
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 7

Question 11.
Suggest a list of metals that are extracted electrolytically.
Answer:
Li, Na, Mg, Ba, Ca, Al

Question 12.
What is the quantity of electricity in coulombs needed to reduce 1 mol of Cr2O-27 ? Consider the reaction :
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 8
Answer:
1 mole Cr2O-27 requires 6 moles electrons for reduction.
∴ Required charge = 6F
= 6 × 96500 coulomb.
= 579000 coulomb.

Question 13.
Write the chemistry of recharging the lead storage battery, highlighting all the materials that are involved during recharging.
Answer:
Lead storage battery : It is a secondary cell i.e., a cell which is rechargeable because the products of cell reaction sticks to the electrode. It is also called as lead storage cells. It consists of six cells connected in series. Each cell consist of spongy lead anode and a grid of lead packed with lead dioxide (PbO2) acts as cathode. An aqueous solution of H2SO4 (38% by mass) acts as electrolyte. The reactions which takes place at electrodes can be represented as:
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 9
Concentration of H2SO4 decreases as sulphate ions are consumed to form PbSO4 during the working of the cell. As a result of this the density of solution also decreases.

Recharging the cell / battery: Lead storage battery can be recharged by connecting it to an external source of direct current. This reverses the flow of electron with the deposition of Pb on the anode and PbO2 on the cathode. That is, during recharging operation the cell behaves as electrolytic cell. Following reaction occurs during recharging.
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 10

Question 14.
Suggest two materials other than hydrogen that can be used as fuels in fuel cells.
Answer:
Methanol (CH3OH), propane (C3H8)

Question 15.
Explain how rusting of iron is envisaged as setting up of an electrochemical cell.
Answer:
Formation of carbonic acid takes place on the surface of iron
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 11
In presence of H+ ion, oxidation of iron takes place
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 12
The electrons are used at other spot where reduction takes place.
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 13
Overall reaction,
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 14

MP Board Solutions

Electrochemistry NCERT Textbook Exercises

Question 1.
Arrange the following metals in the order in which they displace each other from the solution of their salts. Al, Cu, Fe, Mg and Zn.
Answer:
A metal with lesser standard potential (more reactive) can displace the other metal from solution of its salts.
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 15

Question 2.
Given the standard electrode potentials, K+/K = -2.93V, Ag+/Ag = 0.80V, Hg2+/Hg = 0.79V, Mg2+/Mg = -2.37 V, Cr3+/Cr = -0.74V. Arrange these metals in their increasing order of reducing power.
Answer:
The lower the reduction potential, the higher is the reducing power. Hence, the reducing power of the given metals increases in the following order.
Ag < Hg < Cr < Mg < K.

Question 3.
Depict the galvanic cell in which the reaction Zn(s) + 2Ag+(aq) → Zn2+(aq)+ 2Ag(s) takes place. Further show :
(i) Which of the electrode is negatively charged?
(ii) The carriers of the current in the cell.
(iii) Individual reaction at each electrode.
Answer:
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 16
(i) Anode i.e., Zn electrode is negatively charged.
(ii) Electrons are current carriers.

Question 4.
Calculate the standard cell potentials of galvanic cells in which the following reactions take place:
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 17
Calculate the ∆rG°, and equilibrium constant of the reactions.
Solution:
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 18

Question 5.
Write the Nernst equation and emf of the following cells at 298 K :
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 19
Solution:
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 20
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 21
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 22

Question 6.
In the button cells widely used in watches and other devices the following reaction takes place:
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 23
Solution:
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 24

Question 7.
Define conductivity and molar conductivity for the solution of an electrolyte. Discuss their variation with concentration.
Answer:
Conductivity: The conductivity of a solution is defined as the conductance of a solution of 1 cm length and having 1 sq. cm as the area of cross-section.

Molar conductivity: Molar conductivity of a solution at a dilution (V) is the conductance of all the ions produced from one mole of the electrolyte dissolved in V cm3 of the solution when the electrodes are one cm apart and the area of cross-section of the electrodes is so large that the whole of the solution is contained between them. It is usually represented by Λm.

Variation with concentration: The conductivity of a solution (Both for strong and weak electrolytes) decreases with a decrease in the concentration of the electrolyte i.e., on dilution. This is due to the decrease in the number of ions per unit volume of the solution on dilution. The molar conductivity of a solution increase in the decrease in the concentration of the electrolyte i.e., on dilution. This is due to the decrease in the number of ions per unit volume of the solution on dilution. The molar conductivity of a solution increases with decrease in the concentration of the electrolyte. This is because both the number of ions, as well as mobility of ions, increases with dilution. When concentration approaches zero, the molar conductivity is known as limiting molar conductivity.

Question 8.
The conductivity of 0.20 M solution of KCI at 298 K is 0.0248 Scm-1. Calculate its molar conductivity.
Solution:
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 25

Question 9.
The resistance of a conductivity cell containing 0.001M KCl solution at 298 K is 1500Ω What is the cell constant if the conductivity of 0.001M KCl solution at 298 K is 0.146 × 10-3 S cm-1.
Solution:
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 26

Question 10.
The conductivity of sodium chloride at 298 K has been determined at different concentrations and the results are given below :
Concentration/M 0.001 0.010 0.020 0.050 0.100 102 × kSm-1 1.237 11.85 23.15 55.53 106.74 for all concentrations and draw a plot between Λm and C1/2 Find the value calculate Λm and C1/2 Find the value calculate Λm of Λ0m.
Answer:
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 27
Λ0m = intercept on Λm axis = 124-0 S cm2 mol-1 (on extrapolation to zero concentration)
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 28

MP Board Solutions

Question 11.
The conductivity of 0.00241 M acetic acid is 7.896 × 10-5 S cm-1. Calculate its molar conductivity and if Λ0m for acetic acid is 390.5 S cm2 mol-1, what is its dissociation constant?
Solution:
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 29

Question 12.
How much charge is required for the following reductions :
(i) 1 mol of Al3+ to Al.
(ii) 1 mol of Cu2+ to Cu.
(iii) 1 mol of MnO4 to Mn2+.
Solution:
(i) The electrode reaction is :
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 30
(ii) The electrode reaction is :
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 31
(iii) The electrode reaction is :
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 32

Question 13.
How much electricity in terms of Faraday is required to produce
(i) 20.0 g of Ca from molten CaCl2.
(ii) 40.0 g of Al from molten Al2O3.
Solution:
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 33

Question 14.
How much electricity is required in coulomb for the oxidation of
1. 1 mole of H2O to O2
2. 1 mole of FeO to Fe2O3.
Answer:
1. 2H2O → 4H+ + O2 + 4e
2F of electricity is required for the oxidation of 1 mol of H2O

2. Fe2+ → Fe3+ + e
1F of electricity is required for the oxidation of 1 mole of FeO

Question 15.
A solution of Ni(NO3)2 is electrolyzed between platinum electrodes using a current of 5 amperes for 20 minutes. What mass of Ni is deposited at the cathode?
Answer:
According to Faraday’s first law:
W = ZIr [z = \(\frac { M }{ nF } \)]
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 34

Question 16.
Three electrolytic cells A, B, C containing solutions of ZnSO4, AgNO3, and CuSO4, respectively are connected in series. A steady current of 1.5 amperes was passed through them until 1.45 g of silver deposited at the cathode of cell B. How long did the current flow? What mass of copper and zinc were deposited?
Solution:
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 35

Question 17.
Using the standard electrode potentials given in Table 3.1, predict if the reaction between the following is feasible :
(i) Fe3+(aq) and I(aq)
(ii) Ag+(aq) and Cu(s)
(iii) Fe3+(aq) and Br(aq)
(iv) Ag(s) and Fe3+(aq)
(v) Br2(aq) and Fe2+(aq)
Answer:
A reaction is feasible if EMF of the cell is +ve.
Cathode : At which reduction occurs.
Anode : At which oxidation occurs.
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 36
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 37

MP Board Solutions

Question 18.
Predict the products of electrolysis in each of the following:
(a) An aqueous solution of AgNO3 with silver electrodes.
(b) An aqueous solution of AgNO3 with platinum electrodes.
(c) A dilute solution of H2SO4 with platinum electrodes.
(d) An aqueous solution of CuCl2 with platinum electrodes.
Answer:
(i) At cathode:
The following reduction reactions compete to take place at the cathode
Ag+(aq) + e → Ag(s); Eθ = 0.80 V
H+ (aq) + e → \(\frac { 1 }{ 2 }\) H2 (g); Eθ = 0.00V
The reaction with a higher value of Eθ takes place of the cathode. Therefore, deposition of silver will take place at the cathode.

At anode:
The Ag anode is attacked by NO3 ions. Therefore, the silver electrode at the anode dissolves in the solution to from Ag+.

(ii) At cathode: Same as above
At anode: Anode is not attackable and hence OH ions have lower discharge potential than NO3 ions and OH ions react to give O2
OH → OH + e
4OH → 2H2O + O2 (g)
(iii) H2SO4 → 2H+ + SO2-4
HO2 ⇌ H+ + OH

At cathode:
2H++ 2e → H2
At anode: 4OH → 2H2O + O2 + 4e
i. e., H2 will be liberated at cathode and O2 at the anode.

(iv) CuCl2 → Cu2++2Cl
2nd PUC Chemistry Question Bank Chapter 3 Electrochemistry - 18
At Cathode: Cu2+ ions will be reduced in preference to H+ ions
Cu2+ + 2e → Cu
At anode: Cl’ ions will be oxidised in preference to OH ions.
2Cl → Cl2 + 2e
i.e., Cu will be deposited on the cathode and Cl2 will be liberated at the anode.

MP Board Solutions

Electrochemistry Other Important Questions and Answers

Electrochemistry Objective Type Questions

Question 1.
Choose the correct answer:

Question 1.
If specific conductance = K, R = Resistance, l = distance between the electrodes A = Cross-sectional area of a conductor Cm = mol L-1, Ceq = g.eq L-1 then specific resistance of electrolyte will be equal to :
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 38

Question 2.
K is equal to :
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 39

Question 3.
Molar conductivity Λm is equal to :
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 40

Question 4.
Cell constant is :
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 41

Question 5.
For electrolyte (v+ = v = 1) like NaCI:
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 42

Question 6.
Which among the following is not a conductor of electricity :
(a) NaCl(aq)
(b) NaCl(s)
(c) NaCl(mol)
(d) Ag.

Question 7.
By which of the following the resistance of the solution is multiplied to obtain cell constant:
(a) Specific conductance (K)
(b) Molar conductance (Λm)
(c) Equivalent conductance (Λeq)
(d) None of these.

Question 8.
Increase in equivalent conductance of the solution of an electrolyte by dilution is due to:
(a) Increase in ionic attraction
(b) Increase in molecular attraction
(c) Increase in association of electrolyte
(d) Increase in ionization of electrolyte.

Question 9.
If the specific conductance and observed conductance of an electrolyte is same then its cell constant will be :
(a) 1
(b) 0
(c) 10
(d) 1000

Question 10.
Unit of cell constant is :
(a) ohm-1 cm-1
(b) cm
(c) ohm cm
(d) cm-1.

Question 11.
Unit of specific conductance is :
(a) ohm-1
(b) ohm-1 cm-1
(c) ohm-2 cm-1 equivalent-1
(d) ohm-1 cm-2.

Question 12.
If the concentration of any solution is C gram equivalent/ litre and specific resistance is A, its equivalent conductance will be :
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 43

Question 13.
The coating of layer of zinc on iron to prevent it from corrosion is called :
(a) Galvanization
(b) Cathodic protection
(c) Electrolysis
(d) Photoelectrolysis.

Question 14.
A saturated solution of KNO3 is used for salt bridge because :
(a) Speed of K+ is more than NO3
(b) Speed of NO3 is more than K+
(c) Speed of both is nearly same
(d) Solubility of KNO3 is high in water.

Question 15.
Acts as dipolar in dry cells :
(a) NH4Cl
(b) Na2CO3
(c) pbSO4
(d) MnO2

Question 16.
Reduction is known as :
(a) Electronation
(b) De-electronation
(c) Protonation
(d) De-protonation.

Question 17.
What is the path of electric current in a Daniel cell when Zn and Cu electrodes are connected:
(a) From Cu to Zn inside the cell
(b) From Cu to Zn outside the cell
(c) From Zn to Cu inside the cell
(d) From Zn to Cu outside the cell.

Question 18.
In a cell containing Zn electrode and normal hydrogen electrode (NHE), Zn acts like:
(a) Anode
(b) Cathode
(c) Neither cathode nor anode
(d) Both anode and cathode.

Question 19.
If salt bridge is removed from half cells then voltage :
(a) Reduces and becomes zero
(b) Increases
(c) Immediately increases
(d) Does not change.

Question 20.
When lead storage battery is discharged :
(a) SO2 is released
(b) Pb is manufactured
(c) PbSO4 is used
(d) H2SO4 is used.

Question 21.
Process of Rusting of iron is :
(a) Oxidation
(b) Reduction
(c) Corrosion
(d) Polymerisation.

Question 22.
Value of standard potential of hydrogen electrode is :
(a) Positive
(b) Negative
(c) Zero
(d) No definite value.

Answers:
1. (b), 2. (c), 3. (d), 4. (b), 5. (a), 6 (b), 7. (a), 8. (d), 9. (a), 10. (d), 11. (b), 12. (a), 13. (a), 14. (c), 15. (d), 16. (a), 17. (d), 18. (a), 19. (a), 20. (d), 21. (c), 22. (c).

Question 2.
Fill in the blanks :

  1. Acetic acid is a ………………… electrolyte.
  2. Conductance of electrolyte ………………… with the increase in temperature.
  3. On increasing dilution the value of specific conductance of a solution …………………
  4. ………………… decreases with increase in size of ion.
  5. Unit of specific resistance is …………………
  6. Primary cells cannot be ………………… again.
  7. Device which converts chemical energy into electrical energy is known as ………………… cell.
  8. Amount of electric current which produces one gram equivalent of a substance is known as …………………
  9. In metallic conduction ………………… property remains unchanged.
  10. Reciprocal of resistance is known as …………………
  11. Conductance of 1 cm cube of a conductor is called …………………
  12. 1 Faraday is equal to ………………… coulomb.
  13. Rusting of iron is an example of …………………
  14. Potential of standard hydrogen is assumed to be …………………

Answers:

  1. Weak
  2. Increases
  3. Decreases
  4. Conductance
  5. ohm cm
  6. Charged
  7. Electrochemical
  8. Faraday
  9. Chemical property
  10. Conductance
  11. Specific conductance
  12. 96500 coulomb
  13. Corrosion process
  14. 0.0 volt
  15. Electrochemical cell.

Question 3.
Match the following :

I.
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 44
Answers:

  1. (e)
  2. (c)
  3. (d)
  4. (b)
  5. (a).

II.
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 45
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 46
Answer:

  1. (c)
  2. (d)
  3. (b)
  4. (a)
  5. (e)
  6. (f).

Question 4.
Answer in one word / sentence :

1. Give two examples of strong electrolyte.
2. Give two examples of weak electrolytes.
3. What is the effect of temperature on electrolytic conductivity ?
4. Write the formula of Kohlrausch’s law.
5. Write the formula of equivalent conductance.
6. Write the formula of molar conductance.
7. Device which converts electrical energy into chemical energy.
8. What is the potential of both the electrodes of the cell due to which electric current flows in the cell ?
9. What is the potential produced due to redox reaction between a metal electrode and its ions called ?
10. What is the unit of potential difference ?
11. Write the formula of cell constant.
12. Cell which can be recharged are known as.
13. State the unit of Equivalent conductance.
14. What is the chemical composition of rust ?
15. Write the relation between Electromotive force and Equilibrium constant of a cell.
16. What is the name of the reaction in which oxidation and reduction occur simultaneously ?
Answers:
1. Strong electrolyte : HCl, NaOH, NaCl
2. Weak electrolyte : CH3COOH, H2CO3,
3. Conductivity increases
4.
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 47
5. Equivalent conductance
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 48
6.
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 49
7. Electrolytic cell
8. Electromotive force
9. Electrode potential
10. Volt
11. Cell constant = \(\frac { l }{ A } \)
12. Secondary cell
13. Ohm cm2 gm eq-1
14. Fe2O3 . xH2O
15.
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 50
16. Redox reaction.

MP Board Solutions

Electrochemistry Very Short Answer Type Questions

Question 1.
Write the definition of Electrochemical cell.
Answer:
System in which chemical energy is converted to electrical energy by oxidation reduction is known as electrochemical cell or voltaic cell.

Question 2.
What is an Electrolytic cell ?
Ans.
The container or system in which electrical energy is passed by which chemical reaction takes place thus, electrical energy is converted to chemical energy is known as electrolytic cell.

Question 3.
What is Electrode potential ?
Answer:
The potential difference developed between the electrodes and electrolyte of an Electrolytic cell is known as Electrode potential.

Question 4.
What is a strong electrolyte ? Write two examples.
Answer:
Electrolyte which completely dissociate in aqueous solution are known as strong electrolyte.
Example : NaCl, KCl, NH4Cl etc.

Question 5.
What is a weak Electrolyte ? Write two examples.
Answer:
Electrolyte which dissociate partially in aqueous solution are known as weak electrolyte.
Example : NH4OH, CH3COOH, HCN etc.

Question 6.
What is meant by standard electrode potential ?
Answer:
Standard electrode potential (E°) of a half cell is the potential difference when one electrode is dipped in molar solution of its ion at 298 K. If electrode is gaseous the pressure of gas must be one atmosphere.

In IUPAC system, reduction potential are known as standard electrode potential.

Question 7.
Write Ohm’s law.
Answer:
According to Ohm’s law “It states that potential difference across the conductor is directly proportional to the current (I) flowing through it” i.e.,
Mathematically, it can be written as :
I α V
V = IR (R = Resistance, unit = ohm, Ω)

Question 8.
What is cell constant ?
Answer:
For a conductivity cell, the ratio of distance between two electrodes (l) and area of cross-section of electrode (A) is called as cell constant.
∴ Cell constant = \(\frac { l }{ A } \) or x = \(\frac { l }{ A } \)
Unit of cell constant = cm-1.

Question 9.
What is galvanization ? Explain.
Answer:
Iron is coated with the layer of zinc to protect it from rusting. This process is known as galvanization. The galvanized iron articles keep their lustre due to the coating of invisible protective layer of basic zinc carbonate, ZnCO3.Zn(OH)2.

Question 10.
What is Electrochemical Equivalent ?
Answer:
Electrochemical equivalent of a substance is that mass of substance released or deposited on an electrode when a current of one ampere is passed for one second.

MP Board Solutions

Electrochemistry Short Answer Type Questions

Question 1.
What is salt bridge ? Write its two functions.
Answer:
‘U’ shaped tube filled with KCl or KNO3 in Agar-Agar solution or gelatin, is known as salt bridge. It connects the two half cell.
Functions : (i) It allows the flow of current by completing the circuit.
(ii) It maintains the electrical neutrality.

Question 2.
Derive relation between standard electromotive force and equilibrium constant
Answer:
Relation between standard electromotive force and equilibrium constant can be derived using van’t Hoff isochore. For any given reaction equilibrium constant IQ is equal to the ratio of rate constant of forward reaction and rate constant of backward reaction.
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 51
Value of equilibrium constant Kc can be calculated using standard free energy change (∆G°) because
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 52

Question 3.
What do you understand by oxidation-reduction reactions ?
Answer:
Oxidation-Reduction reactions: Chemical reactions in which valency of elements changes are known as oxidation-reduction reactions. In this process both oxidation and reduction reactions occur simultaneously, in which one of the substance is oxidized and the other substance is reduced. Like
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 53
In this reaction FeCl3 is reduced to FeCl2 and SnCl2 is oxidized to SnCl4. In the reaction valency of Fe decreases and valency of Sn increases.

Question 4.
Write difference between Metallic conduction and Electrolytic conduction.
Answer:
Differences between Metallic conduction and Electrolytic conduction :

Metallic conduction:

  1. Metallic conduction takes place by movement of electrons.
  2. There is no chemical change.
  3. There is no transfer of matter.
  4. In metallic conduction conductivity decreases with increase in temperature.

Electrolytic conduction

  1. Electrolytic conduction takes place by movement of ions.
  2. Due to chemical change decomposition of electrolyte takes place.
  3. Transfer of matter takes place as ions.
  4. In electrolytic conduction conductivity increases with increase in temperature.

Question 5.
What are the difference between emf (Cell potential) and potential difference
Answer:
Difference between EMF and Potential difference :

EMF / Cell potential:

  1. It is the potential difference between the two terminals of the cell when no current is flowing in the circuit, i.e., in an open circuit.
  2. It is the maximum voltage which can be obtained from a cell.
  3. It can be measured by potentiaometrie method.
  4. Work performed by electromotive force is the maximum work done by a cell.
  5. It is responsible for continuous flow of current in electric circuit.

Potential difference:

  1. It is the difference of the electrodes potentials of the two electrodes when the cell is sending current through the circuit.
  2. It is the less than the maximum voltage as it is the difference of electrode potential.
  3. It can be measured by simple voltmeter also.
  4. Work performed by potential difference is less than the maximum work done by a cell.
  5. It is not responsible for the continuous flow of current in circuit.

Question 6.
What is specific conductance ? Give its unit.
Answer:
Specific conductivity: The reciprocal of resistivity is called specific conductiv¬ity. It is defined as the conductance between the opposite faces of one centimeter cube of a conductor. It is denoted by K (kappa).
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 54
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 55
The specific conductivity of a solution at a given dilution is the conductance of one cm cube of the solution. It is represented by K (kappa).
Note : The specific conductivity of a solu¬tion of electrolyte depends upon the dilution or molar concentration of the solution.

Question 7.
What is resistivity of any solution ?
Answer:
Resistivity : When current flow in the solution through two electrodes the resistance is proportional to length and inversely proportional to cross-sectional area A.
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 56
The constant p (rho) is called resistivity or specific resistance.
Unit: If l is expressed in cm, A in cm2 and R in ohm, the unit of resistivity will be
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 57
or Resistivity of any solution is the resistance of 1 cm cube.

Question 8.
Differentiate between Electrochemical cell (Galvanic cell) and Electrolytic cell.
Answer:
Differences between Electrochemical and Electrolytic cells :

Electrochemical cell or Galvanic cell:

  1. It is a device to convert chemical energy into electrical energy.
  2. It consists of two electrodes in different compartments joined by a salt bridge.
  3. Redox reactions occurring in the cell are spontaneous.
  4. Free energy decreases with operation of cell, i.e., ∆G < 0.
  5. Useful work is obtained from the cell.
  6. Anode works as negative and cathode as positive electrodes.
  7. Electrons released by oxidation process at anode go into external circuit and pass to cathode.
  8. To set-up this cell, a salt bridge/porous pot is used.

Electrolytic cell:

  1. It is a device to convert electrical energy into chemical energy.
  2. Both the electrodes are in same solution.
  3. Redox reactions occurring in the cell are non-spontaneous.
  4. Free energy increases with operation of cell, i.e., ∆G > 0.
  5. Work is done on the system.
  6. Anode is positive and cathode is negative.
  7. Electrons enter into cathode electrode from external source and leave the cell at anode.
  8. No salt bridge is used in this cell.

Question 9.
What is equivalent conductance ?
Answer:
Equivalent conductance:
“Conductance of total ion produced by one gram equivalent of electrolyte in the solution is called equivalent conductance.” It is denoted by Λeq.
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 58

Question 10.
What is molar conductance ?
Answer:
Molar Conductivity : The molar conductivity of a solution at definite concentration (or dilution) and temperature is the conductivity of that volume which contains one mole of the solute and is placed between two parallel electrodes 1 cm apart and having sufficient area to hold whole of the solution. It is denoted by Λm.
Mathematically,
Λm = K × V …(1)
Where V is the volume in ml in which one gram mole of substance is dissolved.
If M is molarity or m moles are dissolved in 1000 ml.
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 59
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 60

Question 11.
Define cell constant Develop a relation between specific conductance and cell constant.
Answer:
Cell constant: In any conductive cell, the distance between two electrodes and surface area of electrode A are constant. The ratio of l and a is called cell constant i.e.
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 61
Unit of cell constant is cm1 and it is generally expressed by x.
Relation between specific conductance and cell constant : For a conductor, the resistance R is directly proportional to length R and inversely proportional to area of cross – section of electrolyte.
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 62

Question 12.
What are the factors which influence the electrical conductance of electrolytes ?
Answer:
Factor which influence electrical conductivity of electrolytes :

The main factor which influence the electrical conductivity are following:

1. Temperature: It influence following interactions.
(a) Interionic attractions: It depends upon the solute-solute interactions. Which is found between the ions of solute.
(b) Solvation of ions: It depends upon solute-solvent interactions. It is relation between ions of solute and solvent molecules.
(c) Viscosity of solvent: It depends upon solvent-solvent interactions. Solvent molecules are related with each other.
With increase in temperature all these three effects decrease and average kinetic energy of ions increases. Thus, with increase of temperature, resistance of solution decreases and hence conductance increases.

2. Nature of electrolyte : The conductance of solution depends upon the nature of electrolyte. On the basis of conductance measurement electrolytes are classified as strong electrolyte and weak electrolyte. Strong electrolytes have high value of conductance even at higher concentration also.

3. Dilution or concentration : It is main factor which influence electrical conductance. Effect of dilution or concentration can be studied indivisually in equivalent conductance, specific conductance and molar conductance. But for a general concept of electrical conductance of solution as the concentration is lowered or dilution increases, electrical conductance of whole solution increases.

Question 13.
On what factors does the various conductivities of an electrolytic solution depend ?
Answer:
Conductivities of electrolytic solution depend on the following factors :

  1. Dilution : On increasing dilution, value of specific conductance of a solution decreases, value of equivalent conductance and molar conductance increases.
  2. Nature of solvent: A solvent with high dielectric constant has high conductivity and with low dielectric constant has low conductivity.
  3. Number of ions present in solution: Conductivity of strong electrolytes is higher than the conductivity of weak electrolytes.
  4. Size of ion : In aqueous solution, small ions are heavily hydrated due to which their conductivity decreases.
  5. Effect of Temperature: With the increase in temperature conductivity increases.

Question 14.
With the increase in dilution how do specific conductance, Equivalent conductance and molar conductance change ?
Answer:
With the increase in dilution, specific conductance decreases. This is because by the increase in dilution number of ions present in 1 cm cube of solution decreases.
But, Equivalent conductance Λeq = K × V
and Molar conductance Λm = K × V
Equivalent conductance and molar conductance are the product of specific conductance and dilution. By the increase in dilution (or decrease in concentration) magnitude of K decreases but that of V increases.
Increase in magnitude of V is comparatively much more than the decrease in magnitude of K. Thus, by the combined effect of both, by the increase in dilution Λeq and Λm increases.

MP Board Solutions

Question 15.
What is an Electrolytic cell and how does it work ?
Answer:
Electrolytic cells : In these cells electric current is supplied through an external source, as a result of which chemical reactions take place which is called electrolysis like : Electrolysis of water, NaCl, Al2O3 etc. For example in Solvay trough cell electrode is immersed in sodium chloride solution and electric current is passed due to which NaCl electrolyses.

At mercury cathode sodium is released and at anode chlorine is released. Sodium forms amalgam with mercury and is taken out of the cell.
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 63

Question 16.
What is meant by electromotive force of an electrochemical cell ?
Answer:
The difference in electrode potentials of the two electrodes of an electro- chemical cell is known as electromotive force or cell potential. It is expressed in volt.

Due to difference in potential electric current flows from an electrode of lower potential to an electrode of higher potential. EMF of the cell can be expressed in terms of reduction potential as :

Cell potential = Standard electrode potential – Standard electrode potential
of R.H.S. electrode of L.H.S electrode
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 64
EMF of a cell is measured by connecting the voltmeter between the two electrodes of a cell. EMF of a cell depend on the concentration of solutions of both half cells and nature of the two electrodes. For example, In Daniel cell, concentration of CuSO4 and ZnSO4 solutions in the two half cells is 1M and at 298 K EMF of the cell is 1.10 volt.

MP Board Solutions

Electrochemistry Long Answer Type Questions

Question 1.
What is standard hydrogen electrode ? How is it prepared ?
Answer:
Standard hydrogen electrode : This consists of gas at 1 atmospheric pressure bubbling over a platinum electrode immersed in 1 M HC1 at 25°C (298 K) as shown in figure. The platinum electrode is coated with platinum black to increase its surface. The hydrogen electrode thus con¬structed forms a half cell which on coupling with any other half cell begins to work on the principle of oxidation or reduction. Electrode depending upon the circumstances works both as anode or cathode.
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 65

MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 66
Standard hydrogen electrode (SHE) is arbitrarily assigned a potential of zero.

Question 2.
Derive Nernst Equation for single electrode potential.
Answer:
Value of standard electrode potential given in electrochemical series is applicable only when the concentration of electrolyte is 1M and temperature is 298 K. But in electrochemical cells the concentration of electrolyte is not definite and electrode potential depends on concentration and temperature. In such condition single electrode potential can be expressed by Nernst equation.
For a reduction half reaction, Nernst equation can be expressed as follows :
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 67
Where E = Reduction electrode potential
E° = Standard electrode potential (Mn+ concentration 1M and at 298 K)
R = Gas constant = 8.31 JK-1 mol-1 = Temperature (in kelvin) = 298 K
n = Valency of metal ion, F = 1 Faraday (96,500 coulomb)
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 68
Equation (2) is Nernst equation for single electrode potential.

Question 3.
Write the Faraday’s laws of electrolysis.
Answer:
Faraday’s first law of electrolysis : The law states that, “The mass of any substance deposited or liberated at any electrode is directly proportional to the quantity of electricity passed.”
Thus, if W gm of the substance is deposited on passing Q coulomb of electricity, then
W α Q or W = ZQ
Where, Z is a constant of proportionality and is called electrochemical equivalent of the substance deposited. If a current of I ampere is passed for t second, then Q = I × t. So that,
W = Z × Q = Z × I × t
Thus, if Q = 1 coulomb, I = 1 ampere and t = 1 second, then W = Z. Hence, electrochemical equivalent of a substance may be defined as, “The mass of the substance deposited when a current of one ampere is passed for one second.”
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 69
As one faraday (96500 C) deposits one gram equivalent of the substance, hence electrochemical equivalent can be calculated from the equivalent mass.
Faraday’s second law of electrolysis : It states that, “When the same quantity of electricity is passed through solutions of different electrolytes connected in series, the weight of the substances produced at the electrodes are directly proportional to their equivalent mass.”

For example, for CuSO4 solution and AgNO3 solution connected in series, if the same quantity of electricity is passed, then
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 70

Question 4.
What is rusting of iron ? Describe Electrochemical theory of rusting.
Answer:
Corrosion: Process by which the layers of undesirable compounds are formed on the surface of a metal on its exposure to atmospheric condition are called corrosion. Rusting of iron is an example of corrosion, chemically it is Fe2O3xH2O.

Electrochemical theory of rusting :
Anode reaction : On one spot of iron sheet, oxidation takes place and this spot behaves as an anode.
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 71
The electrons which are released at this spot travel through the metal and reach another spot on the metal which acts as cathode. These electrons cause the reduction of oxygen in the presence of hydrogen ions (H+). H+ ions are formed due to decomposition of carbonic acid formed by dissolution of CO2 in H2O.
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 72
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 73

Question 5.
What is corrosion ? Write three factors affecting it and any three methods to prevent it.
Answer:
Corrosion : Process by which the layers of undesirable compounds are formed on the surface of a metal on its exposure to atmospheric conditions are called corrosion.

Factors affecting corrosion :

  1. Nature of metal: Reactive metal corrodes readily.
  2. Impurities in metal: Impure metal corrodes quickly to a greater extent.
  3. Environment: If environment around metal contains oxygens, carbon dioxide, moisture, salts and acidic gases like CO2, SO2, SO3 etc. then corrosion occurs quickly.

Methods to prevent corrosion :

1. Barrier protection : In this method, the surface of the metal is coated with paint, oil or grease. Due to this the surface of the metal remain unexposed to atmospheric conditions and hence corrosion is prevented. Surface of the metal can also be protected by :
(i) Coating metal surface with non-corroding metals like nickel and chromium is called electroplating.
(ii) Dipping iron article in molten metal like zinc. This process is called galvanization.

2. Sacrificial protection : The rusting of iron can be prevented by covering the iron with more electropositive metals like zinc. Zinc metal has more tendency to get oxidized as compared to iron. So, iron articles will not be harmed till the layer of zinc present on its surface hence zinc metal is called the sacrificial metal.

3. Antirust solution : The alkaline antirust solution are employed to prevent rusting, alkaline solution prevent the availability of H+ ions.

In this method, iron articles are dipped in alkaline sodium phosphate or chromate solution. Due to this an insoluble sticking film of iron phosphate is formed on the surface which prevents rusting.

MP Board Solutions

Question 6.
Describe dry cell with labelled diagram.
Answer:
Dry cell: It is a primary cell based on Leclanche cell invented by G. Leclanche in 1868. In a primary cell, the electrode reactions cannot be reversed by an external source of electrical energy. In this cell, the cell reaction takes place only once i.e., this cell is not rechargeable.

It is generally used in torches, transistors, radios, calculators, tape recorders, etc. It consists of a hollow zinc cylinder which is filled with a paste of NH4Cl and a little ZnCl2. This paste is made with the help of water. The zinc cylinder acts as anode while cathode is a graphite rod (Carbon). The carbon rod is surrounded by a black paste of MnO2 and carbon powder. The zinc cylinder has an outer insulation of cardboard case.

Dry cells are sealed with wax or other material to protect the moisture from evaporation. When the electrodes are connected, the cell operates.

The electrode reactions are complex. Metallic Zn is oxidized to Zn2+ and the electrons liberated are left on the container. The reactions which take place at electrodes can be represented as :
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 74

This reaction prevents polarization due to formation of ammonia. It also prevents the substantiaL increase of concentration of Zn2+ ions which would decrease the cell potential. This potential of dry cell is approximately 1.5 V.

Defect: Due to acidic nature of NH4Cl zinc container corrodes due to which holes develop through which the chemicals come out.
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 75
Nowadays, the cells are made leakage resistant. In it KOH is used in place of NH4Cl by which zinc does not corrode.

Question 7.
What is Kohlrausch law ? Give its two applications.
Answer:
Kohlrausch in 1875 gave a generalisation known as Kohlrausch’s law, “At infinite dilution when the dissociation of the electrolyte is complete, each ion makes a definite contribution towards molar conductance of the electrolyte irrespective of the nature of the other ion with which it is associated.”
Or
“The value of molar conductance at infinite dilution is given by the sum of the contributions of ions (cation and anion).”
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 76
Where, λ+ and λ are ionic contributions or ionic conductances of cation and anion while v+ and v are the number of cations and anions in the formula unit of electrolyte.

Applications of Kohlrausch’s law :

(i) Calculation of molar conductance at infinite dilution for weak electrolytes :

Molar conductance or equivalent conductance of weak electrolytes cannot be obtained graphically by extrapolation method, since these are feebly ionized. Kohlrausch’s law enables indirect evaluation in such cases. For example, molar conductances of acetic acid can be obtained from the knowledge of molar conductances at infinite dilution of HCl, CH3COONa and NaCl which are strong electrolytes.

From Kohlrausch’s law, it is clear that
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 77
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 78

(ii) Determination of degree of dissociation :
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 79

Question 8.
Draw a labelled diagram of Daniel cell and explain cell reaction.
Or,
Draw a labelled diagram of electrochemical cell and write cell reaction.
Answer:
Electrochemical cell: In the redox reactions, the transfer of electrons between oxidizing and reducing agents occurs through wire and thus chemical energy changes into electrical energy. The device on which chemical energy changes into electrical energy is called electro chemical cell. These are also known as galvanic or voltaic cells. Working of these cells can be understood with the example of Daniel cell.
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 80
Daniel cell : In this cell, Zn rod is dipped in ZnSO4 solution and Cu rod in copper sulphate solution. Both solutions are connected through KC1 salt bridge. When Zn and Cu electrodes are connected by wire and galvanometer, flow of electrons from Zn to Cu occurs. Zinc atoms change into Zn2+ and electrons reach at Cu electrode, where Cu2+ changes into Cu metal and this copper deposits on electrode.
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 81

MP Board Solutions

Electrochemistry Numerical Questions

Question 1.
On passing 5 ampere electric current for 30 minute through a container filled with AgNO3 10.07 gram silver is deposited, then determine the chemical equivalent of silver. If electrochemical equivalent of hydrogen is 0-00001036 then calculate the equivalent mass of Silver.
Solution:
Given : W = 10-07 gm, i = 5 ampere, t = 30 × 60 second
According to Faraday’s first law W = Zit
∴ 10.7 = Z × 30 × 60
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 82

Question 2.
What are weak electrolytes ? Give one example. Find out molar conductivity of LiBr aqueous solution infinite dilution when joint conductance of Li+ ion and Br ion are 38.7 Scm2 mol-1 and 78.40 Scm2 mol-1 respectively.
Solution:
Weak electrolytes : These are the substances which dissociate only to a small extent.
Examples: CH3COOH,NH4OH
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 83

Question 3.
What are strong electrolytes ? Find out the molar conductivity of aqueous solution of BaCl2 at infinite dilution when ionic conductance of Ba+2 ion and Cl ion are 127.30 Scm2 mol-1 and 76.34 Scm2 mol-1 respectively.
Solution:
Strong electrolytes : These are substances which dissociate almost completely into ions under all dilutions.
Examples: NaCl, HCl,CH3COONa
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 84

Question 4.
Calculate the molar conductance of Al2(SO4)3 if
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 85
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 86
Solution:
By the ionisation of Al2(SO4)3 solution
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 87
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 88

Question 5.
Molar conductivity of \(\frac { M }{ 30 } \) CH3COOH is 9.625 mho and molar conductance of CH3COOH at infinite dilution (Λm) is 385 mho. Calculate the percentage of dissociation of \(\frac { M }{ 30 } \) CH3COOH.
Solution:
Degree of dissociation
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 89

Question 6.
Calculate molar conductance of acetic acid at infinite dilution from following values:
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 90
Solution:
From Kohlrausch’s law,
MP Board Class 12th Chemistry Solutions Chapter 3 Electrochemistry 91

MP Board Class 12th Chemistry Solutions

MP Board Class 11th Physics Solutions भौतिक विज्ञान

MP Board Class 11th Physics Solutions Guide Pdf Free Download भौतिक विज्ञान in both Hindi Medium and English Medium are part of MP Board Class 11th Solutions. Here we have given NCERT Madhya Pradesh Syllabus MP Board Class 12 Physics Book Solutions Bhautik Vigyan Pdf.

MP Board Class 11th Physics Book Solutions in Hindi Medium

MP Board Class 11th Physics Book Solutions in English Medium

  • Chapter 1 Physical World
  • Chapter 2 Units and Measurements
  • Chapter 3 Motion in a Straight Line
  • Chapter 4 Motion in a Plane
  • Chapter 5 Laws of Motion
  • Chapter 6 Work, Energy and Power
  • Chapter 7 System of Particles and Rotational Motion
  • Chapter 8 Gravitation
  • Chapter 9 Mechanical Properties of Solids
  • Chapter 10 Mechanical Properties of Fluids
  • Chapter 11 Thermal Properties of Matter
  • Chapter 12 Thermodynamics
  • Chapter 13 Kinetic Theory
  • Chapter 14 Oscillations
  • Chapter 15 Waves

MP Board Class 11th Physics Important Questions In English Medium

We hope the given MP Board Class 11th Physics Solutions Guide Pdf Free Download भौतिक विज्ञान in both Hindi Medium and English Medium will help you. If you have any query regarding NCERT Madhya Pradesh Syllabus MP Board Class 11 Physics Book Solutions Bhautik Vigyan Pdf, drop a comment below and we will get back to you at the earliest.

MP Board Class 6th Science Solutions Chapter 1 Food: Where Does it Come From?

In this article, we will share MP Board Class 6th Science Solutions Chapter 1 Food: Where Does it Come From? Pdf, These solutions are solved subject experts from the latest edition books.

MP Board Class 6th Science Solutions Chapter 1 Food: Where Does it Come From?

Food: Where Does it Come From? Text Book Exercise

Question 1.
Do you find that all living beings need the same kind of food?
Answer:
No, we know that the different organisms eat different kinds of food. For example, human being eats roti, dal, rice, bread, vegetables and rice, etc. Buffalo, cow and some other animals eats grass, oil cake, grains, hay, etc. Cat and dog eats small animals, milk, roti, bread and birds, etc. Tiger, lion eat other animals. Thus, we can say that different living beings eat different kind of food.

Question 2.
Name the five plants and their parts that we eat?
Answer:

Plants:

  1. Radish
  2. Carrot
  3. Mustard
  4. Potato
  5. Maize

Parts that we eat:

  1. Roots and leaves
  2. Roots
  3. Seeds, oil and leaves
  4. Roots
  5. Fruits

Question 3.
Match the items in Column A with that in Column B.
MP Board Class 6th Science Solutions Chapter 1 Food Where Does it Come From img 2
Answer:

(i) (d)
(ii) (c)
(iii) (a)
(iv) (b)

Question 4.
Fill up the blanks with the words gives:
herbivore, plant, milk, sugarcane, carnivore

  1. Tiger is a ……………………… because it eats only meat.
  2. Deer eats only plants products and so, is called ……………………….
  3. Parrot eats only ………………….. products.
  4. The …………………….. that we drink, which comes from cows, buffaloes and goats is an animal product.
  5. We get sugar from ……………………..

Answer:

  1. Carnivore
  2. Herbivore
  3. Plant
  4. Milk
  5. Sugarcane.

MP Board Solutions

Projects And Activities

Activity 1.
You must have seen a garden lizard around your home. Next time whenever you see it, observe carefully and find out what it takes for food. Is the food different from that of a house lizard?
Answer:
A garden lizard takes mosquitoes, house flies while a house lizard takes insects only.

Activity 2.
Make a list (with pictures, when possible) of food items generally taken by people of different regions of India. Place these on a large outline map of India to display in your classroom?
Answer:
MP Board Class 6th Science Solutions Chapter 1 Food Where Does it Come From img 3

Activity 3.
Find out the names of plants that grow in water and which are eaten as food?
Answer:
Lotus, lily, algae and chest – nut, etc. are grow in water and which are eaten as food.

Activity 4.
Make a table to show that the type of food the animals eat?
Answer:
MP Board Class 6th Science Solutions Chapter 1 Food Where Does it Come From img 4

Activity 5.
In the table give below names of some of the things are given. Write their uses and sources in front of them?
MP Board Class 6th Science Solutions Chapter 1 Food Where Does it Come From img 5
Answer:
MP Board Class 6th Science Solutions Chapter 1 Food Where Does it Come From img 6

Activity 6.
Prepare a table to show animals which eats only plants, other animals and both plants and animals?
Answer:
MP Board Class 6th Science Solutions Chapter 1 Food Where Does it Come From img 7

Activity 7.
Make a table that what do your friends eat?
Answer:
MP Board Class 6th Science Solutions Chapter 1 Food Where Does it Come From img 8

Activity 8.
Make a table to show some food items and their ingredients?
Answer:
Food items and their ingredients
MP Board Class 6th Science Solutions Chapter 1 Food Where Does it Come From img 9

Activity 9.
Prepare a table to show ingredients used to prepare food items and their sources?
Answer:
Ingredients used to prepare food items and their sources
MP Board Class 6th Science Solutions Chapter 1 Food Where Does it Come From img 10

Activity 10.
How will you sprout the seeds?
Answer:

1. Take some dry seeds of chana or raoong.
2. Put a small quantity of seeds is a container filled with water and leave this aside for a day.
3. Next day, drain the water completely and leave the seeds in the vessel. Wrap them with a piece of wet cloth and set aside.
4. The following day, a small white structure may have grown out of the seeds. If so, the seeds have sprouted.

MP Board Class 6th Science Solutions Chapter 1 Food Where Does it Come From img 11

If not, wash the seeds in water, drain the water and leave them aside for another day, covered with a wet cloth.

5. Further, the next day, the seeds would have sprouted.
6. Further, the next day, the seeds would have sprouted.
7. After washing these sprouted seeds, we can eat them.
8. They can also be boiled. Add some spices and get a tasty snack to eat.
MP Board Class 6th Science Solutions Chapter 1 Food Where Does it Come From img 12

Food: Where Does it Come From? Intex Questions

Question 1.
Paheli want to know if any of our food comes from sources other than plants and animals?
Answer:
No.

Question 2.
Paheli wants to know where you would place human beings, while filling table of Activity 6?
Answer:
Omnivoxes.

Food: Where Does it Come From? Additional Important Questions

Objective Type Questions Food: Where Does it Come From?

Question 1.
Choose the correct answer:

Question (a)
Cat is a omnivores because it eats:
(a) Plants
(b) Animals
(c) Both of these
(d) None of these.
Answer:
(c) Both of these

Question (b)
Sugar is made from:
(a) Water
(b) Wheet
(c) Rice
(d) Sugarcane
Answer:
(d) Sugarcane

MP Board Solutions

Question (c)
The source of chicken curry is:
(a) Plants
(b) Animals
(c) Both of these
(d) None of these
Answer:
(b) Animals

Question (d)
Seeds of mustard plants give us:
(a) Oil
(b) Fruit
(c) Both of these
(d) None of these
Answer:
(a) Oil

Question (e)
Human beings are –
(a) Herbivores
(b) Carnivores
(c) Omnivores
(d) None of these
Answer:
(c) Omnivores

Question 2.
Fill in the blanks:

  1. Food is essential for all ………………….. beings.
  2. Animals provides us ……………………..
  3. All animals are …………………… because of their food habits.
  4. Horse is a herbivorous animal because it eats …………………………
  5. Honey is obtained from …………………….

Answer:

  1. Living
  2. Food
  3. Different
  4. Herbivorous
  5. Honey – Bees.

MP Board Solutions

Question 3.
Which of the following statements are true (T) or false (F):

  1. Milk gives us proteins.
  2. Animals that feed on both plants and animals are called omnivorous.
  3. Animals do not provide us food.
  4. All living beings need the same kind of food.
  5. Animals do not depend for their food on plants.
  6. Human beings are omnivores.

Answer:

  1. True
  2. True
  3. False
  4. False
  5. False
  6. True.

Question 4.
Give one word for the following:

  1. Animals which eat plants and plant products only.
  2. Animals which eat other animals.
  3. Animals which eat both plants and animals.

Answer:

  1. Herbivores
  2. Carnivores
  3. Omnivores.

Question 5.
Match the names of same animals in column A with their common food in column B:
MP Board Class 6th Science Solutions Chapter 1 Food Where Does it Come From img 13
Answer:

(i) – (c)
(ii) – (f)
(iii) – (a)
(iv) – (g)
(v) – (b)
(vi) – (e)
(vii) – (d)

Food: Where Does it Come From? Very Short Answer Type Questions

Question 1.
How many materials or ingredients are needed to prepare a dish of boiled rice?
Answer:
Two, i.e., raw rice and water.

Question 2.
What are the sources of rice or wheat?
Answer:
The sources of rice or wheat are fields and plants.

Question 3.
Name some food products we obtain from animals?
Answer:
Milk, egg and meat.

Question 4.
Which animals provide us milk?
Answer:
Buffalo and cow.

Question 5.
Which animals provide us eggs?
Answer:
Hen.

MP Board Solutions

Question 6.
Name some animals that provide us food?
Answer:
Buffalo, cow and goat.

Question 7.
Which parts of a plant are our food?
Answer:
We eat many leafy vegetables. We eat fruits of some plants. Sometimes roots, stems and even flowers of plant are our food.

Question 8.
Name any two oil – yielding plants?
Answer:
Sunflower and mustard plants.

Question 9.
What are herbivorous?
Answer:
The animals which depend on only green plants for their food like cow, goat, etc.

Question 10.
What are carnivorous?
Answer:
The animals which eat only other animals Tiger and Lion are carnivorous.

Question 11.
What are omnivorous?
Answer:
The animals who can feed on plants and other animals both are called omnivorous like man, cat, dog, etc.

Question 12.
Name any two invertebrates?
Answer:

  1. Earthworm
  2. Insects.

MP Board Solutions

Question 13.
What is the food of a frog?
Answer:
Small insects.

Question 14.
What is the food of fishes?
Answer:
It feeds upon microplants and aquatic insects.

Question 15.
Which types of foods are eaten by buffalo and cow?
Answer:
Buffalo and cow eat oil cake, grass, hay, leaf and grain.

Question 16.
What is the smallest constituent of plant or animal?
Answer:
The smallest constituent of plants and animal is cell.

Question 17.
Give one example of each plant which is reproduced by (i) stems, (ii) leaves?
Answer:

  1. Potato, ginger are reproduced by stems.
  2. Bryophyllum is reproduced by leaves.

MP Board Solutions

Question 18.
Where do we get honey?
Answer:
We get honey from honey – bees, which is collected from sweet, juice or nector of flowers.

Question 19.
Name some animals which eat only plants?
Answer:
Buffalo, cow, goat, sheep and deer.

Question 20.
Name some animals which eat both plants and animals?
Answer:
Dog and crow.

Question 21.
Name some animals with lay eggs?
Answer:
Frog, snakes, birds, etc. lay eggs.

Food: Where Does it Come From? Short Answer Type Questions

Question 1.
Name the animals which provide us milk, meat, egg, and honey?
Answer:
We get milk from buffalo, goat, cow and sheep, we get meat from, fish, goat, hen, etc., we get eggs from hens. Honey is obtained from honey – bees.

Question 2.
Name the plants from which we obtained grains, oils, fruits and pulses?
Answer:
We get grains from wheat, rice and maize, etc. we get oils from sunflower, mustard, ground nut and soyabean plants, etc. We get fruits from mango, banana, guava, orange and papaya plants. We get pulses from urad, moong, masoor, and gram plants.

Question 3.
Name the plants from which we obtained vegetables?
Answer:
We get vegetables from radish, brinjal, cabbage, carrot, cauliflower, and peas plants, etc. These vegetables are in the form of roots, stems leaves and fruits.

MP Board Solutions

Question 4.
How are plants different from animals?
Answer:
Difference between plants and animals are:
plants:

  1. All green plants prepare their own food.
  2. Plants cannot move from one place to another. But they show movement only in the position.

Animals:

  1. Animals cannot prepare their own food. They take their food from plants.
  2. Animals can move from one place to another.

Question 5.
Give five examples each of plants producing, cereals, vegetables, fruits, medicines and timber?
Answer:

  1. Cereals plants: Moong, urad, iram, pla, masoor.
  2. Vegetables – Carrot, radish, turnip, cauliflowers and tomato.
  3. Fruits – Apple, guava, orange and mango.
  4. Medicines – Neem, tulasi, podina, ginger and peepal.
  5. Timber – Neem, guava, jamun, babool and palms.

Question 6.
How can plants be classified?
Answer:
Plants can be classified on the basis of following:

  1. Plants can be classified on the basis of their habitat. i.e., water plants, land plants, sea/land plants, water plants, desert plants.
  2. They can be classified on the basis of their structure like herb, shurb or tree.
  3. They can be classified on the basis of their food habits like autotrophic plants, insectivorous plants, heterotrophic plants.

Food: Where Does it Come From? Long Answer Type Questions

Question 1.
Write a short note on the importance of plants and animals in our daily life?
Answer:
Most of the things we use in our daily life are obtained from plants or animals.

  1. Our food items like wheat, rice, pulses, species, oil, vegetables and fruits are obtained from plants.
  2. Milk, ghee, butter, curd, egg and meat are obtained from animals.
  3. Fibers like silk, wool and leather are obtained from animals.
  4. Many materials for shelter house, construction and furniture are also obtained from plants.
  5. Some plants are used for decorative purposes.
  6. Most of the medicines are obtained from living sources. Thus plants are food producing, timber producing, fiber producing and medicine producing source. Plants are also responsible for producing oxygen which is essential for life.
  7. Animal produce very important material for us. Milk, ghee, egg, meat, silk, leather etc. are produced by animals. They plough our fields and work for transportation. In this way we can say that plants and animals are very important for us.

MP Board Solutions

Question 2.
What are similarities and dissimilarities between plants and animals?
Answer:
Similarities between plants and animal:

  1. Both can grow.
  2. Both can respire.
  3. Both can reproduce.
  4. Both can excrete.
  5. Both can show response to stimuli.

Dissimilarities between plants and animals:

  1. Plants can prepare their own food in green leaves with the help of carbondioxide, water, minerals and sunlight. But animals can’t prepare their own food.
  2. Plant’s cannot move from one place to another, but animals can move from one place to another.

MP Board Class 7th Social Science Solutions Chapter 18 Humidity and Rainfall

In this article, we will share MP Board Class 7th Social Science Solutions Chapter 18 Humidity and Rainfall Pdf, These solutions are solved subject experts from the latest edition books.

MP Board Class 7th Social Science Solutions Chapter 18 Humidity and Rainfall

MP Board Class 7th Social Science Chapter 18 Text Book Questions

Choose the correct alternatives from the following

Question 1.
Hail falls in the form of:
(a) Liquid
(b) Solid
(c) Elastic
(d) Gas
Answer:
(b) Solid

Question 2.
Cyclonic rains in the North western part of India occurs during:
(a) Summer Season
(b) Winter Season
(c) Spring Season
(d) Rainy Season
Answer:
(b) Winter Season

MP Board Solutions

Fill in the blanks:

  1. The process of changing of water into vapor is called …………..
  2. When water vapor again changes to liquid or solid state it is known as …………..
  3. The ……………. is an instruments to measure rainfall.

Answer:

  1. Evaporation
  2. condensation
  3. rain gauge

MP Board Class 7th Social Science Chapter 18 Short Answer the Questions

Question 1.
What are water vapors?
Answer:
When very small particles of water are converted to gaseous water molecules are called water vapor.

Question 2.
Why does evaporation increase and decrease?
Answer:
The change in temperature brings about a change in evaporation. The rate of evaporation is more when strong winds blow.

MP Board Solutions

Question 3.
Why are clouds formed?
Answer:
The vapor that rises up from the water bodies reaches high up in the sky and is converted into droplets due to cooling. These droplets get dense and form clouds. When the clouds contain less water droplets it appears white and as its density increases it appears black.

Question 4.
How do you understand by snowfall?
Answer:
The water vapors on reaching higher up in the sky is converted into ice particles due to very low temperature. These ice particles are called snow. When this snow falls on earth it is called snowfall.

Question 5.
What is cyclonic rain?
Answer:
When the hot and cold air meet, the hot air rises upwards and the cold air rushes to occupy the low-pressure area in the center. As a result there is circular movement which causes the whirling air in the center to rise upwards. This rising air cools down, condenses and brings rain. This type of rainfall is called cyclonic rainfall.

MP Board Class 7th Social Science Chapter 18 Long Answer Type Questions

Question 1.
What is condensation? what are its Various forms?
Answer:
The process in which water vapor in die atmosphere changes into minute dip pelts of water or ice crystals is called condensation. Its various forms are dew, frost, fog, smog and hails.

MP Board Solutions

Question 2.
How many types of rainfall are there? Explain with diagram.
Answer:
There are three types of rainfall. They are:

  1. Convectional rain
  2. Orographic rain
  3. Cyclonic rain

1. Convectional rain:
The vapors formed from water bodies due to strong heat rises up in the sky and are condensed due to low temperature there, and falls on the earth in the form of raindrops. This process is called convection. Since the rainfall occurs because of the above – mentioned process, it is called convectional rain. The diagram of convectional rain is given below.

MP Board Class 7th Social Science Solutions Chapter 18 Humidity and Rainfall-1
2. Orographic rain:
When a mountain range lies in the path of a Tain – bearing wind, it causes die wind to rise along its slope. As a result, it cools and gets saturated. Further cooling due to its ascent leads to rainfall. This is called orographic rain. The diagram of Orographic rain is given

MP Board Class 7th Social Science Solutions Chapter 18 Humidity and Rainfall-2
3. Cyclonic rain:
When die hot and cold air meet, the hot air rises upwards and the cold air rushes to occupy the low-pressure area in die center. As a result there is circular movement which causes the whirling air in the center to rise upwards. This rising air cools down, condenses and brings rain. This type of rainfall is called cyclonic rain.
The diagram of Cyclonic rain:

MP Board Class 7th Social Science Solutions Chapter 18 Humidity and Rainfall-3

Question 3.
Make a diagram of rain gauge:
Answer:

MP Board Class 7th Social Science Solutions Chapter 18 Humidity and Rainfall-4

Question 4.
What is humidity? What are the different forms of humidity?
Answer:
The word humidity’ is used to denote die amount of dampness in die atmosphere. In other words the amount of water vapor present in the air is called humidity.

The different forms of humidity:
1. Clouds:
Clouds are formed due to the condensation of water vapor. As the moist air is lifted upwards, it clings to the dust particles in the air to form clouds.

2. Fog:
Fog, as a kind of cloud, is found on or near die surface of the land or water bodies. It is formed by the cooling of the air below its dew point in die lower layers of atmosphere.

3. Rain:
As the clouds arc cooled in the cooler upper region of the atmosphere, the small droplets of water in it grow in size and can no longer float in the air. Falling of these droplets of water from the clouds is called rain.

4. Snowfall:
As condensation takes place at temperature below 0°C, the water-vapor in the atmosphere changes into millions of tiny crystals. Sometimes, they combine together to form flakes of snow. Coming down of these snowflakes to die ground from clouds is termed as snowfall.

5. Hail:
Hails are caused by the rapid ascent of moist air higher regions where temperature is far-below freezing-point This causes the raindrops to freeze. When the hailstones become so big and heavy that the air can no longer hold them, they fall from the cloud on the earth as hailstones.

6. Dew:
On a cold and clear nights moist air comes in contact with cold objects on the earth. The moisture in the air condenses into droplets of water. It is known as dew.

7. Frost:
Frozen dew is called frost In the case of frost, the dew point is or below freezing point 0° Celsius.

MP Board Class 7th General English Letter and Application Writing

In this article, we will share MP Board Class 7th English Solutions Letter and Application Writing Pdf, These solutions are solved subject experts from the latest edition books.

MP Board Class 7th General English Letter and Application Writing

Applications (प्रार्थना पत्र)

Question 1.
Write an application to your school principal for four days leave as you are going out of station.
Answer:
To
The Principal, Janta Junior School,
Gwalior

Sir,
Most respectfully I beg to say that I am a student fo class VII-B. I have to go to Delhi for attending my brother’s marriage. Kindly grant me leave for four days. I shall be highly obliged to you.
Thanking you,

Date : 19th August, 20…..

Yours obediently,
Mukul Jain Roll No. 7
Class VII-A

Question 2.
Write an application to your principal to take you on a picnic.
Answer:
To
The Principal,
Govt. Middle School,
Bhopal

Respected sir,
With due salutations and respect I beg to state that I am the monitor of class VII-A and on behalf of all the students of class VII, I request you to take us to a class picnic. We shall be highly obliged if you grant our request.

Thanking you,
Date : 10th October, 20…..

Yours obediently
Mehul Garg
Class VII-A

Question 3.
Write an application to your principal for two days sick leave.
Answer:
Το
The Principal,
V. J. Middle School, Guna

Sir,
I beg to say that I am suffering from fever since last night i.e., 4th October 20……. Therefore, I won’t be able to attend school. Kindly grant me leave for two days.
Thanking you,
Date : 5th October, 20 ………

Yours sincerely,
Ashutosh Tiwari
Class VII-B

MP Board Solutions

Letters
(पत्र)

Question 1.
Write a letter to your sister, asking her to come and visit you for the coming festival.
Answer:
22, Ashok Nagar,
Indore (West) M. P.
Oct. 11, 20……

My dear sister Anu,

I want to inform you that our parents have decided to celebrate ‘Deepawali’ here with our family. Our elder brother has agreed to reach by 13th of October. Therefore, I request you to come to us and pay a visit for the coming Deepawali on 17th October, 20….. Rest is O. K.

Thanking you,

Yours younger brother,
Mohan G

Question 2.
Write a letter to your friend telling him about the Sports Meet in your school.
Answer:
10, Raghava Pura,
Ram Nagar, Indore
10-2-20……

My dear Mahesh,
In the month of January, ‘Sports Meet’ Programme was held in my school. Different sports took place. Most attractive games were cricket and football. The players of school topped the list of winners of Gold medals. The D. M. was the chief guest. The function was over with a lecture of our Principal. Rest is O. K.

Waiting for your letter.

Yours
Mahendra

Question 3.
Write a letter to your father telling him how you enjoyed your school picnic.
Answer:
School Hostel
4, Rajpur (M.P.)
4 – 5 – 20…….

Respected Father,

The students of class VIII arranged picnic. We hired a bus and reached Government Park. We saw it for the first time. It is very beautiful and attractive. My friends read their poems and sang songs. We all had our lunch there. Then we played antakshari with our teachers. We really enjoyed a lot. Everything was 0. K.

Thanks,
Yours obedient son/daughter,
Mohan/Mohini
Class-VII

Question 4.
You are living in a village and write a letter to our friend to spend the summer vacation with you.
Answer:
Vill.–Sohanpura, Post-Awagarh
Distt. KATNI
January 11, 20…

Dear Harish,
Our school has closed for the summer vacation. Last night, we were talking of you. Father and mother asked me to invite you during the vacations. I needed no pressing as I long to have you in our midst. The rains have set in. The weather is pleasant. The mango trees are laden with sweet juicy fruits and when you come we will enjoy them to our heart’s content. I hope you will not disappoint me.

Very Sincerely yours,
Parishkrat

Question 5.
Write an application to the Principal of your school for full fee concession.
Answer:
The Principal,
H. S. Secondry School,
Gwalior.

Sir,
I am a poor student. My father’s monthly income is only Rs.5000/-. He cannot afford to pay my school fees. I beg to add that I came first at the last examination.

I request you to grant me full fee concession so that I may continue my studies.

Thanking you,

Your most obedient student.
Deepak Sharma
Class VII A
Date : 15 April 20…..

MP Board Class 9th Maths Solutions Chapter 4 दो चरों वाले रैखिक समीकरण Additional Questions

In this article, we will share MP Board Class 9th Maths Solutions Chapter 4 दो चरों वाले रैखिक समीकरण Additional Questions Pdf, These solutions are solved subject experts from the latest edition books.

MP Board Class 9th Maths Solutions Chapter 4 दो चरों वाले रैखिक समीकरण Additional Questions

MP Board Class 9th Maths Chapter 4 अतिरिक्त परीक्षोपयोगी प्रश्न

MP Board Class 9th Maths Chapter 4 दीर्घ उत्तरीय प्रश्न

प्रश्न 1.
दर्शाइए कि बिन्दु A(1, 2), B(-1,-16) और C(0, – 7) रैखिक समीकरण y = 9x – 7 के आलेख पर स्थित है। (2019)
हल:
बिन्दु A(1, 2) के निर्देशांकों का मान समीकरण में रखने पर,
∴ 9x – 7 = 9 x 1 – 7 = 9 – 7 = 2 = y.
⇒ दायाँ पक्ष = बायाँ पक्ष
बिन्दु B(-1, – 16) के निर्देशांकों का मान समीकरण में रखने पर,
∴ 9x – 7 = 9x (-1) – 7 = – 9 – 7 = – 16 = y
⇒ दायाँ पक्ष = बायाँ पक्ष
बिन्दु C(0, – 7) के निर्देशांकों का मान समीकरण में रखने पर,
∴ 9x – 7 = 9 (0) – 7 = 0 – 7 = – 7 =y
⇒ दायाँ पक्ष = बायाँ पक्ष अतः दिए हुए बिन्दु A, B एवं C समीकरण y = 9x – 7 के आलेख पर स्थित हैं।

प्रश्न 2.
रैखिक समीकरण 3x + 4y = 6 का आलेख खींचिए। यह आलेख X-अक्ष और Y-अक्ष को किन बिन्दुओं पर काटता हैं? (2019)
हल:
समीकरण 3x + 4y = 6 (दिया है)
MP Board Class 9th Maths Solutions Chapter 4 दो चरों वाले रैखिक समीकरण Ex 4.4 4
MP Board Class 9th Maths Solutions Chapter 4 दो चरों वाले रैखिक समीकरण Ex 4.4 4a
अतः संलग्न चित्र 4.18 अभीष्ट आलेख है तथा यह आलेख -अक्ष को बिन्दु (2, 0) पर एवं Y-अक्ष को बिन्दु (0, 1\(\frac { 1 }{ 2 }\)) पर काटता है।
MP Board Solutions

प्रश्न 3.
वह रैखिक समीकरण जो फॉरेनहाइट (F) को सेल्सियस (C) में बदलती है, सम्बन्ध c = \(\frac { 5F – 160 }{ 9 }\) से दी जाती है।
(i) यदि तापमान 86°F है, तो सेल्सियस में तापमान क्या है ?
(ii) यदि तापमान 35°C है, तो फॉरेनहाइट में तापमान क्या है ?
(iii) यदि तापमान 0°C है तो फॉरेनहाइट में तापमान क्या है तथा यदि तापमान 0°F है, तो सेल्सियस में तापमान क्या है ?
(iv) तापमान का वह कौन-सा संख्यात्मक मान है जो दोनों पैमानों (मात्रको) में एक ही है ?
हल:
MP Board Class 9th Maths Solutions Chapter 4 दो चरों वाले रैखिक समीकरण Ex 4.4 5

MP Board Class 9th Maths Chapter 4 लघु उत्तरीय प्रश्न

प्रश्न 1.
उस सरल रेखा से निरूपित समीकरण का आलेख खींचिए जो X-अक्ष के समानान्तर है और उसके नीचे 3 मात्रक की दूरी पर है।
उत्तर:
अभीष्ट चित्र संलग्न है।
MP Board Class 9th Maths Solutions Chapter 4 दो चरों वाले रैखिक समीकरण Ex 4.4 6

प्रश्न 2.
उस रैखिक समीकरण का आलेख खींचिए जिसके हल उन बिन्दुओं से निरूपित हैं जिनके निर्देशांकों का योग 10 इकाई है।
हल:
प्रश्नानुसार, अभीष्ट समीकरण होगा : x + y = 10
यदि x = 0 तो 0 + y = 10 ⇒ y = 10
यदि x = 5 तो 5 + y = 10 ⇒ y = 10 – 5 = 5
यदि x = 10 तो 10 + y = 10 ⇒ y = 10 – 10 = 0
MP Board Class 9th Maths Solutions Chapter 4 दो चरों वाले रैखिक समीकरण Ex 4.4 7
अतः उपर्युक्त चित्र अभीष्ट आलेख है।

प्रश्न 3.
समीकरण y = 2x + 1 का आलेख खींचिए। (2019)
हल:
निर्देशः उपर्युक्त प्रश्न के समीकरण की तरह हल कीजिए।

प्रश्न 4.
रैखिक समीकरण x + 2y = 8 का वह हल ज्ञात कीजिए जो निम्नलिखित पर एक बिन्दु निरूपित करता है:
(i) X-अक्ष
(ii) Y-अक्ष।
हल:
(i) चूँकि X-अक्ष पर बिन्दु की कोटि y = 0. इसलिए x + 2 x 0 = 8 ⇒ x + 0 = 8
⇒ x = 8
अतः समीकरण का अभीष्ट हल : x = 8, y = 0.

(ii) चूँकि Y-अक्ष पर बिन्दु की भुंज x = 0. इसलिए
0 + 2y = 8 ⇒ 2y = 8 ⇒ y = 8/2 = 4
अतः समीकरण का अभीष्ट हल : x = 0, y = 4.

प्रश्न 5.
मान लीजिए.y, x के अनुक्रमानुपाती है। यदि x = 4 होने पर y = 12 हो, तो एक रैखिक समीकरण लिखिए। जब x = 6, तोy का क्या मान है ?
हल:
चूँकि y α x
⇒ y = Cx
जब x = 4 होने पर y = 12 हो, तो
12 = C x 4
⇒ C = 12/4 = 3 C का मान समीकरण y = Cx में रखने पर,
y = 3x अतः अभीष्ट समीकरण : y = 3x.
अब x = 6 का मान समीकरण y = 3x में रखने पर,
y = 3 x 6 = 18
अतः एका अभीष्ट मान = 18.
MP Board Solutions

MP Board Class 9th Maths Chapter 4 अति लघु उत्तरीय प्रश्न

प्रश्न 1.
निम्नलिखित कथन सत्य हैं या असत्य लिखिए। अपने उत्तरों का औचित्य दीजिए।
(i) बिन्दु (0, 3) रैखिक समीकरण 3x + 4y = 12 के आलेख पर स्थित है।
(ii) रैखिक समीकरण x + 2y = 7 के आलेख बिन्दु (0, 7) से होकर जाता है।
(iii) सारणी :
MP Board Class 9th Maths Solutions Chapter 4 दो चरों वाले रैखिक समीकरण Ex 4.4 8
से प्राप्त बिन्दुओं के निर्देशांक समीकरण x – y + 2 = 0 के कुछ हलों को निरूपित करते हैं।
(iv)दो चरों वाली रैखिक समीकरण के आलेख का प्रत्येक बिन्दु उस समीकरण का एक हल निरूपित नहीं करता है।
(v) दो चरों वाली रैखिक समीकरण के आलेख का एक सरल रेखा में होना आवश्यक नहीं है।
उत्तर:
(i) कथन सत्य है, क्योंकि बिन्दु के निर्देशांक समीकरण को सन्तुष्ट करते हैं।
(ii) कथन असत्य है, क्योंकि बिन्दु के निर्देशांक समीकरण को सन्तुष्ट नहीं करते हैं।
(iii) कथन सत्य है, क्योंकि बिन्दु (3, -5) के निर्देशांक समीकरण को सन्तुष्ट नहीं करते हैं।
(iv) कथन असत्य है, क्योंकि दो चरों वाली रैखिक समीकरण का प्रत्येक बिन्दु उस समीकरण का एक हल निरूपित करता है।
(v) कथन असत्य है, क्योंकि दो चरों वाली रैखिक समीकरण का आलेख सदैव एक सरल रेखा होती है।

प्रश्न 2.
वह रैखिक समीकरण लिखिए जिसकी कोटि उसके भुज से तीन गुनी है। (2019)
उत्तर:
y = 3x.

MP Board Class 9th Maths Chapter 4 वस्तुनिष्ठ प्रश्न

बहु-विकल्पीय प्रश्न

प्रश्न 1.
रैखिक समीकरण 2x – 5y = 7 :
(a) का एक अद्वितीय हल है
(b) के दो हल हैं
(c) के अपरिमित रूप से अनेक हल हैं
(d) का कोई हल नहीं है।
उत्तर:
(c) के अपरिमित रूप से अनेक हल हैं

प्रश्न 2.
यदि (2,0) रैखिक समीकरण 2x + 3y = k का हल है, तो k का मान है :
(a) 4
(b) 6
(c) 5
(d) 2.
उत्तर:
(a) 4

प्रश्न 3.
रैखिक समीकरण 2x + 3y = 6 का आलेख -अक्ष को निम्नलिखित में से किस बिन्दु पर काटता
(a) (2, 0)
(b) (0, 3)
(c) (3, 0)
(d) (0, 2).
उत्तर:
(d) (0, 2).

प्रश्न 4.
X-अक्ष पर स्थित किसी बिन्दु का रूप होता है :
(a) (x, y)
(b) (0, y)
(c) (x, 0)
d) (x, 4).
उत्तर:
(c) (x, 0)
MP Board Solutions

प्रश्न 5.
रेखा y = x पर स्थित किसी बिन्दु का रूप होता है :
(a) (a, a)
(b) (0, a)
(c) (a, 0)
(d) (a, – a).
उत्तर:
(a) (a, a)

प्रश्न 6.
X-अक्ष की समीकरण का रूप है :
(a) x = 0
(b) y = 0
(c) x + y = 0
(d) x = y
उत्तर:
(b) y = 0

प्रश्न 7.
दो चरों वाला रैखिक समीकरण है : (2019)
(a) ax2 + bx + c = 0
(b) ax + b = 0
(c) ax3 + bx2 + c = 0
(d) ax + by + c = 0.
उत्तर:
(d) ax + by + c = 0.

प्रश्न 8.
x = 5, y = 2 निम्नलिखित रैखिक समीकरण का हल है:
(a) x + 2y = 7
(b) 5x + 2y = 7
(c) x + y = 7
(d) 5x + y = 7.
उत्तर:
(c) x + y = 7

प्रश्न 9.
रैखिक समीकरण 2x + 3y = 6 का आलेख एक रेखा है जो X-अक्ष को निम्नलिखित बिन्दु पर मिलती है:
(a) (0, 2)
(b) (2, 0)
(c) (3, 0)
(d) (0, 3).
उत्तर:
(c) (3, 0)
MP Board Solutions

प्रश्न 10.
(a, a) रूप का बिन्दु सदैव स्थित होता है :
(a) X-अक्ष पर
(b) Y-अक्ष पर
(c) रेखा y = x पर
(d) रेखा x + y = 0 पर।
उत्तर:
(c) रेखा y = x पर

प्रश्न 11.
(a,-a) रूप का बिन्दु सदैव रेखा पर स्थित होता है :
(a) x = a
(b) y = -a.
(c)y = x
(d) x + y = 0.
उत्तर:
(d) x + y = 0.

प्रश्न 12.
दो संख्याओं का योग 25 व अन्तर 5 है, तो वे संख्याएँ होंगी : (2018)
(a) 15, 10
(b) 20, 5
(c) 13, 12
(d) 30, 5
उत्तर:
(a) 15, 10

रिक्त स्थानों की पूर्ति
1. एक ऐसा समीकरण जिसका आलेख एक सरल रेखा होता है, …… समीकरण कहलाता है।
2. रैखिक समीकरण ax + by + c = 0 का आलेख एक ……..रेखा है।
3. x और y का मान युग्म (x, y) जो दिए हुए समीकरण ax + by + c = 0 को सन्तुष्ट करता है, उक्त समीकरण का ………. कहलाता है।
4. जब किसी समीकरण निकाय का कोई भी हल नहीं होता, तब निकाय ……….. निकाय कहलाता है।
5. जब किसी समीकरण निकाय का कोई हल होता है, तब निकाय …………. निकाय कहलाता है।
6. दो चरों वाले एक घात समीकरण का ग्राफ ………… को प्रदर्शित करता है। (2018)
7. यदि एक समीकरण x + 2y = 5 में x = 1 है, तब y का मान ……….. है। (2019)
उत्तर:
1. रैखिक,
2. सरल,
3. हल,
4. असंगत,
5. संगत,
6. सरल रेखा,
7. 2 (दो)।

जोड़ी मिलान
स्तम्भ ‘A’                                      स्तम्भ ‘B’
1. रेखाएँ सम्पाती हों                  (a) y का मान शून्य
2. रेखाएँ प्रतिच्छेदी हों               (b) x का मान शून्य
3. रेखाएँ समानान्तर हों             (c) अनन्ततः अनेक हल
4. रेखा X-अक्ष को काटे            (d) अद्वितीय हल
5. रेखा Y-अक्ष को काटे             (e) कोई हल नहीं
उत्तर:
1. → (c),
2. → (d),
3. → e),
4. → (a),
5. → (b)
MP Board Solutions

सत्य/असत्य कथन
1. समीकरण x + 2y = 5 में यदि x = 1 तो y = 2 होगा।
2. रैखिक समीकरण का आलेख एक वृत्त होता है।
3. दो चरों वाले एकघातीय समीकरण रैखिक समीकरण कहलाते हैं।
4. X-अक्ष का समीकरण x = 0 होता है। (2019)
5. Y-अक्ष, के समानान्तर रेखा का समीकरण x = + a होता है।
6. समीकरण x +2y = 3 का एक हल (1, 1) है। (2019)
7. बिन्दु (0, 5) समीकरण y = 5x + 5 का हल है। (2019)
8. मूल-बिन्दु से गुजरने वाली रेखा का आलेख y = kx रूप द्वारा प्रदर्शित होता है। (2019)
9. रैखिक समीकरण 2x -3y = 0 में चर 2 एवं – 3 है। (2019)
उत्तर:
1. सत्य,
2. असत्य,
3. सत्य,
4. असत्य,
5. सत्य,
6. सत्य,
7. सत्य,
8. सत्य,
9. असत्य।

एक शब्द/वाक्य में उत्तर

1. जब किसी समीकरण निकाय के अनन्ततः अनेक हल हों तो उसका आलेख कैसा होगा?
2. जब किसी समीकरण निकाय का अद्वितीय हल हो, तो उसका आलेख कैसा होगा?
3. जब किसी समीकरण निकाय का कोई हल न हो, तो उसका आलेख कैसा होगा?
4. यदि \(\frac { { a }_{ 1 } }{ { a }_{ 2 } } \neq \frac { { b }_{ 1 } }{ { b }_{ 2 } }\), तो निकाय का हल क्या होगा?
5. यदि \(\frac { { a }_{ 1 } }{ { a }_{ 2 } } =\frac { { b }_{ 1 } }{ { b }_{ 2 } }\neq \frac { { c }_{ 1 } }{ { c }_{ 2 } }\) तो निकाय का हल क्या होगा?
6. यदि \(\frac { { a }_{ 1 } }{ { a }_{ 2 } } =\frac { { b }_{ 1 } }{ { b }_{ 2 } }= \frac { { c }_{ 1 } }{ { c }_{ 2 } }\), तो निकाय का हल क्या होगा?
7. रैखिक समीकरण में चर राशि की उच्चतम घात होती है। (2018)
8. दो.चरों वाला एक रैखिक समीकरण लिखिए। (2019)
9. यदि x = 2, y = 1 समीकरण 2x + 3y =k का हल है, तब k का मान क्या होगा? (2019)
उत्तर:
1. सम्पाती रेखाएँ,
2. प्रतिच्छेदी रेखाएँ,
3. समानान्तर रेखाएँ,
4. अद्वितीय हल,
5. कोई हल नहीं,
6. अनन्ततः अनेक हल,
7. एक,
8. ax + by + c = 0,
9. 7 (सात)।

MP Board Class 6th Special English Solutions Chapter 7 Who Has Seen the Wind

In this article, we will share MP Board Class 6th Special English Solutions Chapter 7 Who Has Seen the Wind Pdf, These solutions are solved subject experts from the latest edition books.

MP Board Class 6th Special English Solutions Chapter 7 Who Has Seen the Wind

Who Has Seen the Wind Text Book Exercise

Word Power

1. Match the column ‘A’ with ‘B’.
MP Board Class 6th Special English Solutions Chapter 7 Who Has Seen the Wind img-1
Answer:
1. → (d)
2. → (a)
3. → (6)
4. → (e)
5. → (c)

Comprehension

Answer these questions:

Question 1.
Has anyone seen the wind?
Answer:
No, no one has seen the wind.

Question 2.
What do the leaves do when the wind is passing through?
Answer:
The leaves hang trembling when the wind is passing through.

Question 3.
How do we know that the wind is passing by?
Answer:
We know that the wind is passing by when the trees bow down their heads.

MP Board Solutions

Let’s Write

Question 1.
Find.out the name of the seasons hidden in this grid and write them in your note books.
MP Board Class 6th Special English Solutions Chapter 7 Who Has Seen the Wind img-2
Answer:
Winter, Autumn, Spring.

Who Has Seen the Wind Word Meanings

Page 1: Trembling – shaking, कांपना Bow – bend, झुकना!