MP Board Class 8th Social Science Solutions Chapter 27 Our Life and Environment

MP Board Class 8th Social Science Solutions Chapter 27 Our Life and Environment

MP Board Class 8th Social Science Chapter 27 Text Book Exercise

Choose the correct alternative from the following:

Question 1.
Is not a biodegradable waste:
(a) vegetables
(b) fruits
(c) paper
(d) polythene bags
Answer:
(d) polythene bags

MP Board Class 8th Social Science Chapter 27 Short Answer Type Questions
Question 1.
What are industrial waste? Give examples.
Answer:
Almost every industry generates different types of wastes, many of which are hazardous to all types of life. The wastes can be solid, liquid or gaseous. These wastes can cause destruction to the environment. The waste material contains ignitable, corrosive, reactive and topic elements. Examples, as, dust, sulphuric acid, hydrochloric acid, SO2, CO2, CO2 gases and plastic waste etc.

Question 2.
What are the processes of manufacturing of goods?
Answer:
Manufacturing of goods involve three processes.

1. Assembly:
It is the combinations of parts to make the final product, for example, a bicycle is assembled by joining various parts.

2. Alteration:
It is the modifying of the raw material into a new material or final product for example sawing of trees into lumbar.

3. Extraction:
In this process one or more components from the raw material for example petrol is extracted from the crude oil.

There are many proofs of early production like bricks used in the buildings earthen pots to store grains etc. All there were produced with hands. As civilization grew the method of production improved because of innovation for example fibres take from different sources are processed to forms cloth.

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Question 3.
Name the major components of industry?
Answer:
Most of the manufacturing industries need four imparts capital, raw material, technology and labour.

1. Capital:
Every industry needs two types of capital Finance capital and physical capital. The physical capital is building, machinary etc and finance capital is money.

2. Raw Material:
Most of the industries rely on raw materials provided by natural resources. These natural resources may be renewable on non renewable.

3. Technology:
The technology advancement have hed to tremendous industrial growth innovations in the field of technology can transform the culture of the society.

4. Labour:
It refers to the workforce. Labour unions are formed who negotiate their wages and work with the owners.

MP Board Class 8th Social Science Chapter 27 Long Answer Type Questions

Question 1.
How does agriculture and cattle affect the environment?
Answer:
In modern agriculture use of fertilizers is increasing day by day in order to enhance the production. Fertilizer are beneficial for increasing the production of foodgrains, it has an advance effect on environment 60% of fertilizers are used by plants, remaining fertilizer gets soluble in rain water and reaches lakes, revised and ponds by which the surface good ground water.

This gets polluted, various insecticides and pesticides which protect the crop from insects and diseases pollute the environment. Cattle are reared in large number to get animal products. Increasing number of cattle has adverse effect. Artificial reproduction of animals through cloning produce economically lucrative breeds, it may lead to diminishing bio-diversity.

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Question 2.
Explain the methods of solid waste disposal?
Answer:
The various methods of solid waste disposal are:

1. Recycling:
It is very old method in which the waste materials are made reusable. All the metal products can be melted to make new products. Plastic, glass and paper is roofs recyclable.

2. Landfill:
It is the common method of disposing waste on land. It is also the cheapest means because transport cost is the only major expenditure. In a modem landfill the solid waste is spread in this layers. Each layer is solidified by bulldozer before the next layer is deposited on them trees are planted there.

3. Composting:
It is a process of decomposing solid waste to make fertilizers. Biodegradable waste is decomposed by microorganisms and it is used as a manner.

4. Incinerators:
In the incinerator the waste is burned so that it reduces weight and volume around 90%.

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Question 3.
What do yo understand by environment friendly technology? Explain.
Answer:
Modern technology can makes industries safe and cost effective. Modern technology is designed to
recycle the various component of manufacturing system.

For example:

  • The scrap steel of automobile industry can be useful to mixed with other metals produce a new metal.
  • The smoke scrubbers remove all the dangerous gases and particulate matter from the discharge of industrial plants.
  • Some industries release their chemical waste into rivers and lakes. Modem technologies have evolved many techniques to secure such waste.
  • In transport sector use of CNG has reduced the pollution level.
  • Modem computer aided machines have proved to be accurate and economical.
  • As modem energy conservation sources the leaves of some plants are used to produce bio-diesel.

Question 4.
Describe the natural and regional environmental issues?
Answer:
National environmental issues. The govt, of India has created agencies to check the pollution and has passed Environment Protection Act, Factories Amusement Act, Central Motor Vehicle Trucks etc. Govt, agencies as well as NGO’s work to check the pollution govt, of India provided enough money for functioning these agencies and departments.

Pollution Central Board at national level as well as state level has been established. These boards has been authorised to survey the area and fix the responsibility. The guilty is persisted in the court.

Regional environmental issues:
At this level a variety of steps have been taken by the govt. NGO’s for the convservation of environment. At local level the municipality or municipal corporations plays a direct role in the water disposal. The sewage of the city is drained to distant parts from the city.

MP Board Class 8th Social  Science Solutions

MP Board Class 8th Social Science Solutions Chapter 26 Study of Local Map

MP Board Class 8th Social Science Solutions Chapter 26 Study of Local Map

MP Board Class 8th Social Science Chapter 26 Text Book Exercise

MP Board Class 8th Social Science Chapter 26 Very Short Answer Type Questions

Question 1.
Which are the three main landforms of surface?
Answer:
Mountains, Plains and Plateaus are the major landforms.

Question 2.
Which are the two methods to show the landform?
Answer:

There are two methods to show the landforms:

  1. Colour method
  2. Contours method.

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Question 3.
What are contour lines?
Answer:
Contour:
A contour is an imaginary line drawn on a map which joins the points of the same height above sea-level. Contrours are the most accurate and common form of showing the landforms.

Question 4.
In what colours plain, platform and mountain are shown in a map?
Answer:
Plains are shown in green colour, Dark green colour shows the high plains. The high rising places are shown in yellow colour, while the colour of high plateau is grey. The low height mountains is of dark grey or light brown colours and the high mountains are shown with the darkbrown colour.

Question 5.
Show the conical hill and plateau through contour lines?
Answer:
Conical hills:
The contour lines are also of equal distance and equal round. If you see such contour lines in the map you will easily know that this is conical hill.

MP Board Class 8th Social Science Solutions Chapter 26 Study of Local Map

Plateau:
The top of plateau is more or less flat is represented by very few contours but its sides are steep and they are shown by closely spaced contours on a map.

MP Board Class 8th Social Science Solutions Chapter 26 Study of Local Map 2

Question 6.
What do the light blue and dark blue colours indicate?
Answer:
Depth of sea is shown by various shades. The sea is shown in map by blue colour, sea nearby land surface is shown by light blue colour. As the depth of sea increases the blue colour becomes darker. The deep and trenches of sea is indicated by the very dark blue colour.

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Project Work

Make a local map of your village or city and then discuss with colleagues in class.

The local map contains following conventional signs.

  1. Contour lines
  2. Road
  3. Forest
  4. Field
  5. Pond
  6. River
  7. Residential areas.

With the help of local map, write in your exercise book.

Question 1.
Which landforms are being shown by the contour lines?

Question 2.
In which direction river is flowing?

Question 3.
Which landform is near forest?

Question 4.
Which is the landform between field and residential area?

Mp Board Class 8th Social Science Solutions Chapter 26 Studies image 3

MP Board Class 8th Social Science Solutions

MP Board Class 8th Maths Solutions Chapter 8 राशियों की तुलना Intext Questions

MP Board Class 8th Maths Solutions Chapter 8 राशियों की तुलना Intext Questions

MP Board Class 8th Maths Chapter 8 पाठान्तर्गत प्रश्नोत्तर

पाठ्य-पुस्तक पृष्ठ संख्या # 127

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प्रयास कीजिए (क्रमांक 8.1)

प्रश्न 1.
एक प्राथमिक विद्यालय में अभिभावकों से पूछा गया कि वे अपने बच्चों के गृह कार्य में सहायता करने के लिए प्रतिदिन कितने घण्टे व्यतीत करते हैं। 90 अभिभावकों ने \(\frac{1}{2}\) घण्टे से 1\(\frac{1}{2}\) घण्टे तक सहायता की। जितने समय के लिए अभिभावकों ने अपने बच्चों की सहायता करना बताया उसके अनुसार अभिभावकों का वितरण संलग्न आकृति में दिखाया गया है जो इस प्रकार है –
20% ने प्रतिदिन 1\(\frac{1}{2}\) घण्टे से अधिक सहायता की, 30% ने 1\(\frac{1}{2}\) घण्टे से 1\(\frac{1}{2}\) घण्टे तक सहायता की, 50% ने बिल्कुल नहीं की।
MP Board Class 8th Maths Solutions Chapter 8 राशियों की तुलना Intext Questions img-1
इसके आधार पर निम्नलिखित प्रश्नों के उत्तर दीजिए –

  1. कितने अभिभावकों का सर्वे किया गया?
  2. कितने अभिभावकों ने कहा कि उन्होंने सहायता नहीं की?
  3. कितने अभिभावकों ने कहा कि उन्होंने 1\(\frac{1}{2}\) घण्टे से अधिक सहायता की?

हल:
1. माना कि x अभिभावकों का सर्वे किया।
चूँकि 30% अभिभावकों ने \(\frac{1}{2}\) घण्टे से 1\(\frac{1}{2}\) घण्टे तक गृहकार्य कराने में अपने बच्चों की सहायता की। अब प्रश्नानुसार,
\(\frac{30}{100}\) × x = 90
x = \(\frac{90×100}{100}\) = 300
अतः कुल 300 अभिभावकों का सर्वे किया गया।

2. क्योंकि 50% अभिभावकों ने कहा कि उन्होंने सहायता नहीं की।
अतः ऐसे अभिभावकों की संख्या = 300 का 50%
= \(\frac{50}{100}\) x 300 = 150
अतः 150 अभिभावकों ने सहायता नहीं की।

3. 20% अभिभावकों ने 17 से अधिक सहायता की। अतः अभिभावकों की संख्या = 300 का 20%
= \(\frac{20}{100}\) x 300 = 60
अतः 60 अभिभावकों ने घण्टे से अधिक सहायता की।

MP Board Class 8th Maths Solutions

MP Board Class 8th Social Science Solutions Chapter 24 Economic Development of Australia Continent

MP Board Class 8th Social Science Solutions Chapter 24 Economic Development of Australia Continent

MP Board Class 8th Social Science Chapter 24 Economic Development of Australia Continent

MP Board Class 8th Social Science Chapter 24 Text Book Exercise

Choose the correct option of the following

Question 1.
From which metal aluminium is made?
(a) Copper
(b) Bauxite
(c) Mica
(d) Tin
Answer:
(b) Bauxite

Question 2.
The original people of New Zealand are called:
(a) Mawaris
(b) Aboriginal
(c) Eskima
(d) none of above
Answer:
(d) none of above

Question 3.
The capital of Australia is
(a) Sydney
(b) Canberra
(c) Perth
(d) Wellington
Answer:
(a) Sydney

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Fill in the blanks:

  1. The main crop of Australia continent is …………
  2. The high quality wool is obtained from ………… sheep.
  3. The worship place of Australian people is called …………
  4. The farming is done in Australia on ………….. percent land.

Answer:

  1. Wheat
  2. Marino
  3. Yuluroo
  4. 4%

MP Board Class 8th Social Science Chapter 24 Very Short Answer Type Questions

Question 1.
Write the name of the biggest rail route in Australia Continent?
Answer:
The Trans-Australian Railways is the biggest rail network in Australia that runs between Sydney (eastern coast) and Perth (in the west) the total length of this route is 4000 kms.

Question 2.
Write the name of famous gold mines in Australia?
Answer:
Kalgoorlie and Coolgardie are the famous gold mines in western Australia.

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Question 3.
Which island is situated in south-east of Australia?
Answer:
Tasmania Island lies in the south-east of Australia.

Question 4.
Which are labourers called who work on sheep-rearing centres?
Answer:
The labourers who work on sheep rearingh are called Jackarooes. They graze sheeps and attend them.

MP Board Class 8th Social Science Chapter 24 Short Answer Type Questions

Question 1.
Where and why grapes are cultivated in Australia continent?
Answer:
A variety of fruits are also grown in Australia. While in South grapes are grown in abundance. The climate of this region is suitable for grape-farming. The wine made of grapes is exported.

Question 2.
Which are the favourable conditions for the farming of wheat in Australia Continent?
Answer:
Wheat is the most important crop of Australia. Half of the total land under cultivation is used for producing wheat. There are big farms here. All the farming works are done by machines. The wheat is produced in winter.

The main wheat producing areas are downs, plains, coastal western-southern Australia and Kenterburry plains of New Zealand. Here the fertile soil, the temperature climate and normal rains are suitable for the wheat crop.

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Question 3.
Which are the major minerals found in Australia ? Write the names of producing areas?
Answer:
In the major part of Australia there are mountains plateaus and deserts. It is one of the oldest land in the world. There are mines of iron ore, bauxite, manganese and gold. Besides these, silver, uranium, thorium, copper and tin mines in abundance in Australia. Kalgoorlie and Coolgardie are the famous gold mines in western Australia.

There are also big mines in Queensland. Bauxite is in plenty in Australia but fairly good amount is used by its own industries hence it is exported in less quantity. Aluminium is made of bauxite. Opal a milky colour metal is found here which is used in manufacturing of bangles and things.

Coal is found in the mines of New South Wales, Queensland and New Zealand. Natural Oil and Gas are found in the Downs and Western Coastal Australia.

MP Board Class 8th Social Science Chapter 24 Long Answer Type Questions

Question 1.
Why sheep rearing industry is advanced in Australia?
Answer:
Sheeps are mainly reared for wool in Australia. Few sheep are reared for meat also. Nearly 18 crore sheeps are reared in Australia Continent. Here sheeps are kept in big farm house which is called sheep rearing centre. These Centres spread in several kilometres.

The region lying near Murray-Darling rivers are most suitable for sheep rearing. New South Wales, Victoria, Queensland and New Zealand are Chief Centres for sheep rearing. Marino sheeps are nearest for wool. Very high quality wool is achieved from Marino sheeps. The wool is taken by machines from the sheep.

The wool is graded and pressure into bales and then exported Marino wool fatches high prices so it is economically beneficial. Because sheeps are reared in abundance so this industry is becoming advance in Australia.

Question 2.
Where and why dense population is found in Australia?
Answer:
The high population is mostly in south-east, south-west and eastern coastal area in Australia. These regions are plains and agriculture is main occupation of the people of Australia like India, the original people of Australia is known as aboriginal and original people of New Zealand are known as Maories. So south-east, South-west and eastern coastal areas are densely populated.

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Question 3.
Mention about two chief industries of Australia Continent?
Answer:
Australia has made treremendous progress in industrial sector and this all is due to the use of latest technology. The high-level administration capability cheap and skilled labour and competitive industrial policy are the main factors of industrial development in Australia.

The two main industries are:

  1. Iron and Steel industry
  2. Woollen clothes.

Most of the manufacturing industries are located in New South Wales, Victoria and New Zealand. Besides these two industries there are agriculture machines, motor vehicles, electrical goods, chemicals, papers, ships, machine tools and oil machines, milk products, cotton clothes tinned fruit and meat industries.

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Project Work

Show the following in the map of Australia continent.

  1. Any one wheat producing area
  2. Goldmines of Kalgoorlie and Coolgardie
  3. NewZealand, Tasmania islands
  4. One state of sheep rearing
  5. Melbourne Brisbane and Sydnv cities
  6. The first last stations of Trans-Australian rail route.

MP Board Class 8th Social Science Solutions Chapter 24 Economic Development of Australia Continent

MP Board Class 8th Social Science Solutions

MP Board Class 8th Social Science Solutions Chapter 23 Australia-Geographical features

MP Board Class 8th Social Science Solutions Chapter 23 Australia-Geographical features

MP Board Class 8th Social Science Chapter 23 Australia-Geographical features

MP Board Class 8th Social Science Chapter 23 Text Book Exercise

Choose the correct option of the following.

Question 1.
(i) The main latitude line passing through the middle of Australia Continent is:
(a) Tropic of Cancer
(b) Equator
(c) Capricorn
(d) None of the above
Answer:
(c) Capricorn

Question 2.
Which is Island Continent?
(a) Antarctica
(b) Australia
(c) Asia
(d) North America
Answer:
(b) Australia

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Question 3.
Which is the country of Australia Continent?
(a) Fizi
(b) Cuba
(c) Chile
(d) Bornio
Answer:
(a) Fizi

Question 4.
In which region of Australian Continent, lies the Great Barrier Reef?
(a) South-East region.
(b) North-East region
(c) North-West region
(d) North-West region
Answer:
(b) North-East region

MP Board Class 8th Social Science Chapter 23 Very Short Answer Type Questions

Question 1.
The area of Eyre Lake which is in the Central lowlands where rivers falls into lakes is known as?
Answer:
The major area around the Eyre Lake is known as inland drainage area. Where the rivers, which can not reach the sea, fall into the inland lakes.

Question 2.
What is called the high but narrow long belt plateaus in Australian Continent?
Answer:
There is parallel expansion of this mountain ranges from the Cape York Peninsula in east coast to the Tasmania island in the south. They form a long belt of the high plateaus which are known as the Great Dividing Range.

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Question 3.
What name the sea landform made by coral insects in the east coast of Australia is known?
Answer:
Along the north-east cost of Australia extends very long coral ridge known (racks of coral) as the Great Barrier Reef. This world famous reef is more than 1920 kms. in length. It is made of skeletons of tiny insects called corals.

Question 4.
Which is the emblem animal and famous tree of Australia?
Answer:
The Kangaroo is the national animal of Australia and Eucalyptus is the main tree

MP Board Class 8th Social Science Chapter 23 Short Answer Type Questions

Question 1.
Why is the western part of Australia Continent?
Answer:
Western Plateau is in Western part of Australia. It occupies two-thirds of the continent and lies from north to south. Due to lack of rain the most of the plateau is desert or semi-desert. The northern part is Great Sandy Desert and southern part is occupied by Great Victoria Desert.

Question 2.
Mention about the Inland drainage of Australia continent?
Answer:
An extensive low land between the western and eastern highlands extends from the gulf of Carpentaria in north to the southern and shores of Australia. Many rivers flow in the lowland but most of the rivers could not reach the sea and fells into the inland lakes.

The biggest Lake Eyre is situated in this area. So the major area around the Eyre Lake is known as inland drainage area. The Inland drainage area is a system where the river flowing, instead of felling in the sea, falls in some water areas there.

Question 3.
Write the climate of Australia?
Answer:
Australia lies in the southern Hemisphere. Most of Australia is dry. The eastern, north-eastern and the western part of the country come in the way of winds blowing on the sea. This part receives heavy rainfall.

The following types of climates are found in Australia.

  1. Desert type in the vast interior of the earth.
  2. Mediterranean type of climate is found in southern coast of Australia.
  3. Monsoon type of climate in northern part of Australia causes rain in summer.

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Question 4.
Write about the prominent animals of Australia continent?
Answer:
Australia is known for Kangaroos and Koala called the mansupials animals. Mansupials have a pouch like fold of skin near the stomach in which they carry their young ones. The other animals are dingo, a wild dog. Platypus is a four legged animal that lays eggs like a bird.

Question 5.
What is Downs? Explain
Answer:
The Middle regions of Australia which receive little rain fall have trees and gray equally. There are two types of grasslands here. In the north there is tropical grass land and in the south of Murray-Darling Basin has temperate grassland which is known is ‘Downs’ also.

Question 6.
Mention about the physical features of New Zealand Island?
Answer:
In the south-east of Australia lies New Zealand. New Zealand is the mountain island. In the north and south islands there stretches a mountain range from north to south. In the southern island this mountain range is called south Alps. The narrow Cook Strait divides the north and south islands of New Zealand.

MP Board Class 8th Social Science Chapter 23 Long Answer Type Questions

Question 1.
Discuss the physical divisions of Australia?
Answer:
Australia can be divided into three major physical divisions. They are:

  1. Western Plateau
  2. The Central Lowlands and
  3. The Eastern Highlands
  4. The Western Plateau

1. The western plateau:
The western plateau of Australia is a vast plateau occupying two thirds of the continent. This part of Australia is a desert or a semi-desert. Desert type of vegetation consisting mainly small shrubs and thorny bushes is found here. In North West the desert area is known as Great Sandy Desert and in its south it is called the Great Victoria Desert.

This part of plateau is rich in minerals especially in gold. Kalgoorlie and Coolgradie gold. Kalgoorlie and Coolgradie goldmines are famous in this area.

2.The Central Lowlands:
There are extensive lowlands between the western plateau and the Eastern Highlands. They extend from the Gulf of Carpentraia in the north, across the continent to the southern shore of Australia.

These are the lowlands so much so that at Lake Eyre, the land is about 12 metres below sea level. The Murray and the Darling are the major rivers of Australia flowing through the Central lowland. Most of the rivers of this area do not reach the sea.

They infect, fall into Are inland lakes. Thus the area around Lake Eyre is a region of inland drainage. The north-eastern part of the plain is occupied by the Great Artesian Basin, Artesian well supply some water to this semi-desert area.

3. The Eastern Highlands:
Along the east coat of Australia are found long belt of elevate plateaus. They extend from Cape York Peninsula in the north to Tasmania in the south. These elevated plateaus are known as the Great Dividing Range. They are broad low in the north whereas in the south they are narrow and high. They also called Great Dividing Range.

4. Coastal plains:
There is oceanic water all around the continent, hence there are narrow coastal plain in the continent. The sea sand and water-borne soil on the mouth of rivers is found here. Along the north east coast of Australia. There is a very long coral ridge known as the Great Barrier Reef.

The Coral reefs have colorful beings and vegetations. New Zealand is the mountain island. The narrow Cook Strait divides the north and south islands of New Zealand.

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Question 2.
What is Great Barrier Reef?
Answer:
Great Barrier Reef:
Off the northeast coast of Australia extends a very long edge like feature known as the Great Barrier Reef. It has been formed as a result of the deposition of skeleton of carols. Corals are tiny sea animals when the corals die their hard skeletons remain fixed in places and new coral grow upon them.

The accumulations of these corals are known as coral Reefs. The world famous Great Barriers Reef made of these corals in more than 1900 kilometers, in length and its distance from coast varies from 30 to 240 kilometers.

Question 3.
Write in detail about the vegetations and animals of Australia Continent.
Answer:
The vegetations are found in Australia as per rain distribution. The Coastal areas which receive
heavy rains abound with long trees and forests. The Western and central dry land are full of thorny bushes and grass. Tropical forests are found in the northern and north-eastern coastal regions of Australia which receive heavy rains they are like monsoon forests. But they are evergreen.

The important trees that grow in these forests are Devdar, Date, Bamboo, Baobab and Bottle. The Eucalyptus is the main tree.

The Koala animal mostly lives on these trees and eats the leaves of eucalyptus trees. The middle regions of Australia which receive little rain have trees and grass equally. In the north there is tropical grass land and in the south of Murray-Darling basin has temperate grass-lands which is known as‘Downs’.

Kangaroo is the national animal of Australia. Emu, Kookaburra and Lyre Bird are other different birds, Kiwis and Penguins are famous birds of New Zealand. Dingo, a wild dog and Platypus are other animals of Australia.

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Project Work

Show the following on the outline map of Australia continent.

  1. Tasmania and New Zealand
  2. Fizi and Papua New Guinea
  3. Grat Victoria and Great Sandy Desert
  4. Murray and Darling rivers,
  5. Great Dividing Range and Great Barrier Reef,
  6. Grasslands of Downs
  7. The Cook Strait.

MP Board Class 8th Social Science Solutions Chapter 23 Australia-Geographical features img 1

MP Board Class 8th Social Science Solutions

MP Board Class 7th Maths Solutions Chapter 15 ठोस आकारों का चित्रण Ex 15.4

MP Board Class 7th Maths Solutions Chapter 15 ठोस आकारों का चित्रण Ex 15.4

प्रश्न 1.
निम्नलिखित ठोसों के ठीक ऊपर एक जलता हुआ बल्ब रखा गया है। प्रत्येक स्थिति में प्राप्त छाया के आकार का नाम बताइए। इस छाया का एक रफ चित्र बनाने | का प्रयास कीजिए। (पहले आप प्रयोग करने का प्रयास करें और फिर उत्तर दें।)
MP Board Class 7th Maths Solutions Chapter 15 ठोस आकारों का चित्रण Ex 15.4 image 1
हल:
जब बल्ब की रोशनी निम्नलिखित ठोसों पर पड़ती | है, तो उनकी छाया का आकार निम्न रूप में दिखाई पड़ता है –

  1. गेंद की छाया वृत्त के रूप में दिखाई पड़ती है।
  2. बेलनाकार पाइप की छाया एक आयत के रूप में दिखाई देती है।
  3. एक पुस्तक की छाया एक लगभग आयत की तरह दिखाई देती है।

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प्रश्न 2.
यहाँ कुछ 3-D वस्तुओं की छायाएँ दी गई हैं, जो उन्हें एक ओवरहैड प्रोजेक्टर के लैम्प (बल्ब) के अन्तर्गत या नीचे रखकर प्राप्त की गई हैं। प्रत्येक छाया से मिलान वाले ठोस की पहचान कीजिए (इनमें एक से अधिक उत्तर हो सकते हैं।)
MP Board Class 7th Maths Solutions Chapter 15 ठोस आकारों का चित्रण Ex 15.4 image 2
हल:

  1. दी हुई छाया एक प्लेट अथवा गोले को निरूपित करती है।
  2. दी हुई छाया एक घन को निरूपित करती है।
  3. दी हुई छाया एक शंकु अथवा जोकर की टोपी को निरूपित करती है।
  4. दी हुई छाया घनाभ अथवा बेलन को निरूपित करती है।

प्रश्न 3.
जाँच कीजिए कि क्या ये कथन सत्य हैं:

  1. एक घन एक आयत के आकार की छाया दे सकता है।
  2. एक घन एक षद्भुज के आकार की छाया दे सकता है।

उत्तर:

  1. सत्य
  2. असत्य।

MP Board Solutions

पाठ्य-पुस्तक पृष्ठ संख्या # 307

प्रयास कीजिए

प्रश्न 1.
पाठ्य-पुस्तकमें दियेगयेप्रत्येकठोसकेलिए,तीन दॄश्य (1), (2) और (3) दिए हैं। प्रत्येक ठोस के लिए संगत ऊपर के, सामने के और पार्श्व दृश्यों की पहचान कीजिए।
उत्तर:

(a) → (1) → सामने, (2) → पार्श्व, (3) → ऊपर
(b) → (1) → ऊपर, (2) → पार्श्व, (3) → सामने
(c) → (1) → पाव, (2) → सामने, (3) → ऊपर
(d) → (1) → पार्श्व, (2) → ऊपर, (3) → सामने।

प्रश्न 2.
पाठ्य-पुस्तक में दिये गये प्रत्येक ठोस का, तीर द्वारा सूचित दिशा से उसे देखने पर एक दृश्य खींचिए।
हल:
ठोस का तीर द्वारा सूचित दिशा में देखने पर दृश्य
MP Board Class 7th Maths Solutions Chapter 15 ठोस आकारों का चित्रण Ex 15.4 image 3

MP Board Class 7th Maths Solutions

MP Board Class 7th Maths Solutions Chapter 15 ठोस आकारों का चित्रण Ex 15.3

MP Board Class 7th Maths Solutions Chapter 15 ठोस आकारों का चित्रण Ex 15.3

प्रश्न 1.
आपको कौन-सा अनुप्रस्थ काट प्राप्त होता है जब आप निम्नलिखित ठोसों को
(i) ऊर्ध्वाधर रूप से और, (ii) क्षैतिज रूप से काटते हैं ?

(a) एक ईंट
(b) एक गोल सेब
(c) एक पासा
(d) एक बेलनाकार पाइप
(e) आइसक्रीम शंकु।

हल:
MP Board Class 7th Maths Solutions Chapter 15 ठोस आकारों का चित्रण Ex 15.3 image 1
पाठ्य-पुस्तक पृष्ठ संख्या # 305-306

MP Board Class 7th Maths Solutions

MP Board Class 8th Social Science Solutions Miscellaneous Questions 2

MP Board Class 8th Social Science Solutions Miscellaneous Questions 2

Write the correct options to the following questions

Question 1.
In which language newspapers was established by Raja Ram Mohan Roy?
(a) Bengali
(b) Hindi
(c) English
(d) Urdu
Answer:
Bengali.

Question 2.
By which constitutional amendment primary education was included in fundamental rights?
(a) 81st
(b) 86th
(c) 87th
(d) 83rd
Answer:
(b) 86th.

Question 3.
Employment for how many days has been ensured under Gramin Rozgar Guarantee Bill
(a) Entire year
(b) 100 days
(c) 200 days
(d) None of these
Answer:
(b) 100 days

Question 4.
Who is the head of Indian Defense Forces?
(a) Defense Minister
(b) Prime Minister
(c) President
(d) Chief Justice of the Supreme Court
Answer:
(c) President.

Question 5.
North America Extends from east to west.
(a) 7200 km
(b) 6400 km.
(c) 4006 km.
(d) 2700 km.
Answer:
(b) 6400 km.

Question 6.
The average density of population in North America.
(a) 51 persons per square kilometers
(b) 21 persons per square kilometers
(c) 22 persons per square kilometers
(d) 104 persons per square kilometers
Answer:
(b) 21 persons per square kilometers.

Question 7.
What is the height of the worlds highest water fall Angel on river Orinoko.
(a) 979 meter
(b) 799 meters
(c) 997 meters
(d) 907 meters
Answer:
(a) 979 meters

Question 8.
The largest producer Country of banana in the world is –
(a) Bolivia
(b) Chile
(c) Ecuador
(d) Peru
Answer:
(c) Ecuador

MP Board Solutions

Fill in the blanks:

  1. In 1876 Queen of England was declared …………….. of India.
  2. Satya sodhak society in Maharashtra was founded by ……………
  3. The percentage of literate women in M.P. as per 2001 census is …………
  4. Indian government set up planning commission in ………………
  5. The army has been organised in …………….. commands.
  6. The woodcutter in Canada is called …………….
  7. ……………… is the capital of Mexico
  8. Of the total land of South America ……………. percent land is worth agriculture.

Answer:

  1. Empress
  2. Jyotika Phule
  3. 50.28%
  4. 1950
  5. 5
  6. lumber jacks
  7. Mexico city
  8. 10%

MP Board Class 8th Social Science Miscellaneous Questions 2 Very Short Answer Type Questions

Question 1.
What was Sargent Scheme?
Answer:
The 1919 Act entrusted the responsibility of education department to provincial councils. Under the Sergent Plan in 1944 free and, compulsory education was made for the children between 6 to 14 years. Initially the British education policy might have not been beneficial to Indians but it played major role in motivating Indians towards nationality and to get united.

Question 2.
Write in brief about Parsis Reform Movements.
Answer:
In 1851 Parsis founded a religious reform union which aimed at renovating the social conditions of Parsis society and reestablished the pristine glory of Parsi religion. Dadabhai Naoroji and Naoroji Furdoonji were among the pioneers of religious and social reformers in Parsi community and brought out a journal Rast Goftar and both played an important role in the spread of girls education.

Question 3.
Which are the major social problems?
Answer:
The major social problems are Social and Economic Unequality:

1. Communal-ism:
Such feelings and activities which consider their own faith superior and treat other faiths and religions as inferior.

2. Caste-ism:
Caste is such a unit which binds the members in marriage and food styles. The members could not come out from cell of Caste-ism and so they fail to play vital role in society.

3. Terrorism:
The terrorists want to convey the messages to people through fear and terror. The religious fanatics indulge in killing innocent people.

4. Discrimination among sex:
In our society some people dislike girl child to be bom so they kill the girl child.

5. Child labor
6. Illiteracy
7. Drinking of liquor and drug Addiction

Question 4.
What do you mean by Cottage industry?
Answer:
Cottage and small scale industries is the traditional industry as it needs little money and goods are made by the family members. These industries produce various traditional products like baskets, small toys, bidis, ropes, envelopes, papad, mats, badi, spices and weaving items etc. poor people can earn money without much capital. Now government is giving facilities to promote this industry.

MP Board Solutions

Question 5.
Write important naval warships of Navy?
Answer:
Main Naval fleet of India are – INS Nilgiri, Himgiri, Devgiri, Taragiri, Vindhyagiri and INS Godavari Navy has survey ships and petrol aircraft carriers. Besides these there are two fleets one is the western fleet and the second is eastern fleet which are the mobile commander on the sea.

Question 6.
What is Cordilleras?
Answer:
The western part of North America continent is a vast mountainous region known as the western Cordilleras which is spread from Alaska in north to Mexico in South.

Question 7.
Which is called the biggest meat market of the world?
Answer:
The central part of South America continent is called the biggest meat market of the world. Argentina, Uruguay, Paraguay, Venezuela are main countries which rear cattle and sheep for meat and milk products.

Question 8.
What is Inter – Mountainous Plateau?
Answer:
The Plateau which lies between the two mountains is called inland mountain plateau. For example. Great Basin.

Question 9.
Why Brazil is called the “Home of Coffee”?
Answer:
Brazil is the largest producer of coffee in the world of it is called the Home of Coffee.

MP Board Solutions

MP Board Class 8th Social Science Miscellaneous Questions 2 Short Answer Type Questions

Question 1.
Write note on the growth of press in 19th century.
Answer:
The press played vital role in taking the idea of reform movements to the people. Earlier the press, newspaper, magazines and journals were under British control but in 19th century the reformers thought to use press as strong medium to convey the feelings of social, religious movements and nationalism to the people so they started their own press, magazines.

A lot of Editors were jailed by British who voiced the grievances and raised national sentiments by their papers. But they continued to use the press and they exposed the plights and suffering of Indians being meted out by the British before the world. Some leading Newspapers were.

  1. The Hindu
  2. The Indian Mirror
  3. Amrit Bazar
  4. Patrika
  5. The Kessari
  6. Maratha
  7. Swadesh Mitra
  8. Prabhakar
  9. Indra Prakash

These papers played a important role in social and religious reforms and the strengthened the Indian National Movements.

Question 2.
What are the demerits of liquor addiction?
Answer:
Liquor drinking is a social evil. This habit is ruining a number of families in India.

  1. A drunkard tortures his children and woman at home and this spoils the peace of family life.
  2. This increases economic problem.
  3. Such families do not get respect.

It ruins health, it damages brain, heart, kidney, liver etc. Drug re-habitation centers and spiritual sermons are quite helpful. Gandhiji tried to eradicate this evil. It was due to his teaching that prohibition has been included in part IV of the Indian Constitution under Directive Principles.

Question 3.
How is plantation farming done?
Answer:
Plantation farming:
The large plantation of plants and tree for trade purpose and production like industries is called plantation farming. There are big plantation regions of coffee and sugarcane in South America where these are produced in greater quantity.

Question 4.
Why wood cutting starts in winter in Canada?
Answer:
In the south of Tundra in Canada, the wide stretch of east to west experiences very cold winter and the summer normal. In this entire area the coniferous forest belt are found. Heavy rainfall occurs here. The earth becomes marshy and deep in summer. So tree cutting in summer is impossible.

In winter heavy snowfalls so the earth and rivers are snow covered. Therefore lumber jacks cut trees in winter. They put the logs on the snow – covered rivers. When the snow of the rivers melt in summer, the logs are also transported and so the woods reach to work shops without labor expense and in short time.

MP Board Solutions

Question 5.
Make a chart of the Air Force officials hierarchy?
Answer:

MP Board Class 8th Social Science Solutions Miscellaneous Questions 2 img 1

MP Board Class 8th Social Science Solutions Miscellaneous Questions 2 img 2

Question 6.
Write the significance of agriculture in the economy of North America?
Answer:
Agriculture has very significant role in the economy of North America. It is very rich in agricultural production. This is mainly because the continent is vast and possesses very fertile plains, suitable climate and sufficient water is available for irrigation. The agricultural products can be classified in two parts:

  • food grains
  • Cash crops.

Extensive Prairie grasslands in the central and the river valleys are suitable for farming. Extensive agriculture is the chief farming practice. Wheat, maize, barley, millet, rice, soybean is main cereal crops are cotton, groundnut, tobacco, fruits are its cash crops. In the economy of North America agriculture has its main role.

Question 7.
Which is called Laplata Basin?
Answer:
Laplata plain:
The third plain is made of highlands of Brazil, Parana, Paraguay’ in south – west and valleys of Uruguay Rivers. This is called Laplata Basin.

Question 8.
Make a list of the items of import and export of South America?
Answer:

MP Board Class 8th Social Science Solutions Miscellaneous Questions 2 img 3

MP Board Class 8th Social Science Miscellaneous Questions 2 Long Answer Type Questions

Question 1.
Explain the relation of princely states of India with British government after 1858.
Answer:
In 1855 there were 562 states ruled by Indian rulers. The Queen’s proclamation had promised not to extend the British territories in India and to respect the rights dignity and honor of Indian princess but it proved mere eyewash. In 1874 the King of Baroda was dethroned. In 1876 Queen Victoria became the Empress of India. She further reduced the power and status of the Indian princes.

Now it was the responsibility of British Govt, in India to protect the Indian states from internal as well as external threats. This gave unlimited powers and to British Government to intervene in the internal affairs of Indian states. Governor General Lord Curzon even banned the foreign travel by Indian princes and he fixed the number troops that. Indian states could maintain under the control of British officers.

Question 2.
What changes do you find in the status of woman in today’s family? Mention it?
Answer:
The plight of women in India was worst. The Purdha system, child marriage, sati system, illiteracy among women were the major features of Indian society. But with the efforts made by social reformers in 1829 the British GOVT, in India banded the Sati System. Above mentioned social evils came to an end. Now women are literate and they are progressing in every field.

We can see women as doctors, teachers, clerks, leaders, police officers, lawyers, Ridges etc in our society. Today, Indian Govt, is Helping women in advancing in every field. Stress is given on girl education. Sonia Gandhi is the President of Congress.

Sheila Dixit is C.M. of Delhi. Today woman is more powerful and their status m our families is equal to men’s status. Now we are proud of woman such as Kalpana Ciiawia a space Scientist. Now we have to change our attitude towards the Indian woman.

Question 3.
Corruption is an economical problem? How?
Answer:
To get own s work done in favor people pay either money or other things to a person or any agency, is called corruption. Stealing of taxation also comes under this category According to law both who pays and vie who receives money through corruption are criminals. The corruption creates economic inequality and the poor gets more poor. Corruption eats into the roots of progress. The govt, has made rule and law to curtail corruption even though corruption is increasing in every field.

MP Board Solutions

Question 4.
Write a note on the production of defense equipment.
Answer:
Defense production activities are divided into two groups departmentally run ordinance of factories:

  • The army ammunition, tanks, vehicles etc. are made in ordinance factories.
  • The defence public sector undertaking produce ships, aircraft, bulldozer earth moving equipment, machines, tools, sensors, communication equipment etc. The Missiles are produced to strengthen the defense line gni, Prithvi. Trishul. Nag, Akash, Brahmastra are successful missiles of India. India has atomic power also.

Question 5.
Write note on the distribution of rain in North America?
Answer:
North America continent received most of its rain fall during summer. There are three western regions which get heavy rainfall:

  • In the inland due to the effect of trade winds.
  • In Central America and South-East areas due to closeness of Gulf Stream.
  • Due to the westerly winds on the western coast of British Columbia.

As we proceed from east coast to western areas, the distribution of rainfall becomes very low. The Arizona desert in south-west of United States have very scantly rainfall .

Question 6.
Describe the major forest industries of North America?
Answer:
The main industries of paper, pulp, furniture and samuoor are situated in North America. Canada has tropical and temperate forests. The useful tress Chit, Fir, Sp-nice and Balsam are in plenty. U.S. and Canada have paper and pulp industries.

Cellulose obtained from soft wood is used in manufacturing, rayon cloth. Hardwood from tropical forest and chuckle gum from Chuckle trees are obtained. The dairy cable are reared in grasslands, meat industry is highly developed near lakes. Chicago is the biggest meat market.

MP Board Solutions

Question 7.
Write about physical divisions of South America?
Answer:
South America is divided into following three divisions:

  1. The Western Coastal Strip
  2. The Western Mountains
  3. The Central Plains
  4. The Eastern Highlands

1.The Western Coastal Strip:
Consists of a narrow strip of low and long the pacific coast in the western part of South America.

2.The Western Mountains:
There is a mountainous range called Andes along the western part of South America. They are the young fold mountains only next to Himalaya Mountains. They are three main ranges in the Andes. Eastern sides of this area have two high ranges.

Between these mountains some plateaus are found. The Bolivian is one of them. Lake Titicaco is also located here. It is one of the largest lake of South America. Mt. Aconcagua is the highest peak as higher as 7021 meters above sea level of Andes. Mt. Cotopaxi in Equator is volcanic mountain of this region.

3.The Central Plain:
The Central Plain is made up of the basins of the Orinoco, the Amazon and Plato rivers.Amazon river which 6280 kilometers long takes the greatest volume of water in the world.

4.The Eastern Highlands:
Consists of Guyana and Brazilians Highlands. The highest waterfall of the world called Angel Fall is located here in the south-eastern part of Venezuela.

Question 8.
Describe the animal husbandry and sheep rearing in South America?
Answer:
Pastoral farming means rearing of animals for milk and milk product, meat, wool, hide and skins etc. Systematic pastoral farming is done m Argentina. Cattle are reared on large pastoral farms spreading over several square kilometers of land Farming is done in a systematic way means that the pastoral farms are run on the lines of big factory. Each aspects of cattle rearing is kept in mind and provisions made for caring each aspect.

For example, there are cattle, fodder crops, physical, machinery, water supply and transport. Cattle are looked after by gauchos. Cattle are sent to the ports for export. They are slaughtered and each part is utilized. For example bones are used for making fertilizers. Hides and fats are other products. Meat packing and beef-extracting factories are also located at ports.

MP Board Class 8th Social Science Solutions

MP Board Class 7th Maths Solutions Chapter 14 सममिति Ex 14.1

MP Board Class 7th Maths Solutions Chapter 14 सममिति Ex 14.1

प्रश्न 1.
पाठ्य-पुस्तक में दी गई छेद की हुई आकृतियों की प्रतिलिपियाँ बनाकर (खींचकर) उनमें से प्रत्येक की सममित रेखाएँ ज्ञात कीजिए।
हल:
सममित रेखाएँ बिन्दुकित रेखाओं से निरूपित हैं।

MP Board Class 7th Maths Solutions Chapter 14 सममिति Ex 14.1 image 1
MP Board Class 7th Maths Solutions Chapter 14 सममिति Ex 14.1 image 2
MP Board Class 7th Maths Solutions Chapter 14 सममिति Ex 14.1 image 3

MP Board Solutions

प्रश्न 2.
पाठ्य-पुस्तक में दी गई आकृतियों में सममित रेखा (रेखाएँ) दी हुई हैं। अन्य छेद ज्ञात कीजिए।
हल:
निम्नांकित आकृतियों में अन्य छेद दर्शाए गए हैं :
MP Board Class 7th Maths Solutions Chapter 14 सममिति Ex 14.1 image 4

प्रश्न 3.
पाठ्य-पुस्तक में दी हुई आकृतियों में दर्पण रेखा (अर्थात् सममित रेखा) बिन्दुकित रेखा के रूप में दी गई है। बिन्दुकित (दर्पण) रेखा में प्रत्येक आकृति का परावर्तन करके, प्रत्येक आकृति को पूरा कीजिए। (आप बिन्दुकित रेखा के अनुदिश एक दर्पण रख सकते हैं और फिर प्रतिबिम्ब (image) के लिए दर्पण में देख सकते हैं)। क्या आपको पूरी की गई आकृति का नाम याद है ?
हल:
प्रत्येक आकृति की पूर्ण आकृति (परावर्तित आकृति) दर्शाई गई है:
MP Board Class 7th Maths Solutions Chapter 14 सममिति Ex 14.1 image 5
MP Board Class 7th Maths Solutions Chapter 14 सममिति Ex 14.1 image 6

प्रश्न 4.
पाठ्य-पुस्तक में दी हुई आकृतियों में से प्रत्येक में विविध सममित रेखाओं (यदि हों तो) की पहचान कीजिए।
हल:
निम्नांकित आकृतियों में विविध सममित रेखाएँ दर्शाई गई हैं:
MP Board Class 7th Maths Solutions Chapter 14 सममिति Ex 14.1 image 7

MP Board Solutions

प्रश्न 5.
पाठ्य-पुस्तक में दी हुई आकृति की प्रतिलिपि बनाइए। किसी एक विकर्ण की सममित रेखा लीजिए तथा कुछ और वर्गों को इस तरह छायांकित कीजिए कि यह आकृति इस विकर्ण के अनुदिश सममित हो जाए। क्या ऐसा करने की एक से अधिक विधियाँ हैं ? क्या यह आकृति दोनों विकर्णों के अनुदिश सममित होगी?
हल:

  1. आकृति विकर्ण AC के अनुदिश सममित है।
  2. चूँकि आकृति EF और GH के अनुदिश सममित हैं। अत: यह एक से अधिक रेखा के अनुदिश सममित है।
  3. यह आकृति विकर्ण BD के भी अनुदिश सममित है।
    MP Board Class 7th Maths Solutions Chapter 14 सममिति Ex 14.1 image 8

प्रश्न 6.
पाठ्य-पुस्तक में दिये हुए आरेखों की प्रतिलिपियाँ बनाइए तथा प्रत्येक आकार को इस तरह पूरा कीजिए ताकि वह आकार दर्पण रेखा (या रेखाओं) के अनुदिश सममित हो।
हल:
आरेखों की दर्पण रेखा के अनुदिश सममिति निम्न प्रकार है:
MP Board Class 7th Maths Solutions Chapter 14 सममिति Ex 14.1 image 9

प्रश्न 7.
निम्नलिखित आकृतियों के लिए सममित रेखाओं की संख्याएँ बताइए:

(a) एक समबाहु त्रिभुज
(b) एक समद्विबाहु त्रिभुज
(c) एक विषमबाहु त्रिभुज
(d) एक वर्ग
(e) एक आयत
(f) एक समचतुर्भुज
(g) एक समान्तर चतुर्भुज
(h) एक चतुर्भुज
(i) एक समषट्भुज
(j) एक वृत्त

हल:

(a) एक समबाहु त्रिभुज – 3 सममित रेखाएँ
(b) एक समद्विबाहु त्रिभुज – 1 सममित रेखा
(c) एक विषमबाहु त्रिभुज – 0 (शून्य) समपित रेखा
(d) एक वर्ग – 4 सममित रेखाएँ
(e) एक आयत – 2 सममित रेखाएँ
(f) एक समचतुर्भुज – 2 सममित रेखाएँ
(g) एक समान्तर चतुर्भुज – 0 (शून्य) सममित रेखा
(h) एक चतुर्भुज – 0 (शून्य) सममित रेखा
(i) एक समषट्भुज – 6 सममित रेखाएँ
(j) एक वृत्त – असीमित सममित रेखाएँ

प्रश्न 8.
अंग्रेजी वर्णमाला के किन अक्षरों में निम्नलिखित के अनुदिश परावर्तन सममिति (दर्पण परावर्तन से सम्बन्धित सममिति) है :
(a) एक ऊर्ध्वाधर दर्पण
(b) एक क्षैतिज दर्पण
(c) ऊर्ध्वाधर और क्षैतिज दर्पण दोनों।
हल:
(a) एक ऊर्ध्वाधर दर्पण में निम्न अंग्रेजी वर्णमाला के अक्षरों में परावर्तन सममिति है :
A, H, I, M, O, T, U, V, W,X और Y.

(b) क्षैतिज दर्पण के अनुदिश अंग्रेजी अक्षर, जिनमें परावर्तन सममिति है:
B,C, D, E, H, I,O और X.

(c) अंग्रेजी अक्षर, जिनमें ऊर्ध्वाधर और क्षैतिज दर्पणों के अनुदिश परावर्तन्द सममिति है :
H, I, O और X.

MP Board Solutions

प्रश्न 9.
ऐसे आकारों के तीन उदाहरण दीजिए, जिनमें कोई सममित रेखा न हो।
उत्तर:
ऐसे आकार जिनमें सममित रेखा नहीं है :

  1. एक विषमबाहु त्रिभुज
  2. एक अनियमित चतुर्भुज
  3. अक्षर F.

प्रश्न 10.
आप निम्नलिखित आकृतियों की सममित रेखा के लिए अन्य क्या नाम दे सकते हैं ?
(a) एक समद्विबाहु त्रिभुज
(b) एक वृत्त।
उत्तर:

(a) माध्यिका
(b) वृत्त का व्यास।

पाठ्य-पुस्तक पृष्ठ संख्या # 288 प्रयास कीजिए

प्रश्न 1.
(a) क्या अब आप एक समबाहु त्रिभुज के लिए, घूर्णन सममिति के क्रम को बता सकते हैं (संलग्न आकृति) ?
MP Board Class 7th Maths Solutions Chapter 14 सममिति Ex 14.1 image 10
(b) जब उपरोक्त त्रिभुज को उसके केन्द्र के परितः (चारों ओर) 120° के कोण पर घुमाया जाता है, तो कितनी स्थितियों में त्रिभुज (स्थिति के अनुसार) पहले जैसा ही लगता है ?
हल:
(a) ∵ ऐसी तीन स्थितियाँ हैं जहाँ कि त्रिभुज एक जैसे दिखाई देंगे। अतः इसमें क्रम 3 की घूर्णन स्थितियाँ हैं। (120°,240°,360°)
(b) यहाँ केवल एक स्थिति होगी, जबकि त्रिभुज ठीक पहले जैसी स्थिति में दिखाई देगा, जबकि इसे केन्द्र के परितः 120° पर घुमाया जाएगा।

प्रश्न 2.
निम्नलिखित में से कौन-से आकारों (संलग्न आकृति) में अंकित बिन्दुओं के परितः (चारों ओर) घूर्णन सममिति है।
MP Board Class 7th Maths Solutions Chapter 14 सममिति Ex 14.1 image 11
हल:
क्योंकि हम जानते हैं कि जब कोई आकृति एक कोण के द्वारा एक बिन्दु पर घूर्णन करती है और पहले जैसी दिखाई देती है, तो उसे घूर्णन सममिति कहते हैं। इस प्रकार, आकृति (i), (ii) व (iv) में घूर्णन सममिति है।

इन्हें कीजिए

दो एक जैसे (सर्वांगसम चतुर्भुज खींचिए, एक समान्तर चतुर्भुज ABCD एक कागज पर तथा दूसरा समान्तर चतुर्भुज A’B’C’D’ एक पारदर्शक शीट (Transparent sheet) पर। उनके विकर्णों के प्रतिच्छेद बिन्दुओं को क्रमशः 0 और 0′ से अंकित (या व्यक्त) कीजिए। समान्तर चतुर्भुजों को इस प्रकार रखिए कि A’ शीर्ष A पर रहे, B’ शीर्ष B पर रहे, इत्यादि।

इन आकारों में, अब बिन्दु O पर एक पिन लगाइए। अब पारदर्शक शीट को दक्षिणावर्त दिशा में घुमाइए।
MP Board Class 7th Maths Solutions Chapter 14 सममिति Ex 14.1 image 12

प्रश्न (i) एक पूरे चक्कर में पारदर्शकशीट पर बना आकार कागज पर बने आकार से कितनी बार संपाती होता है।
(ii) इसमें घूर्णन सममिति का क्या क्रम है ?
हल:
(i) जब हम पारदर्शक शीट को दक्षिणावर्त दिशा में घुमाते हैं, तो दो स्थितियाँ प्राप्त होती हैं। पहली स्थिति में जब शीर्ष A’ शीर्ष A पर होता है और दूसरी स्थिति में शीर्ष A’ शीर्ष C पर होता है। इससे स्पष्ट होता है कि पूरा चक्कर घुमाने (360°) पर समान्तर चतुर्भुज की दो स्थितियाँ हैं, जहाँ यह एक जैसा दिखाई देगा।
(ii) इसमें क्रम 2 की घूर्णन सममिति होगी।

पाठ्य-पुस्तक पृष्ठ संख्या # 289

प्रयास कीजिए

MP Board Solutions

प्रश्न 1.
दी हुई आकृतियों के लिए x से अंकित बिन्दु के परितः घूर्णन सममिति का क्रम बताइए (संलग्न आकृति)।
MP Board Class 7th Maths Solutions Chapter 14 सममिति Ex 14.1 image 13
हल:
जब आकृति (i) को अंकित बिन्दु के परितः घुमाया जाता है, तो यह आकृति चार स्थितियों (90°, 180°,270° और 360°) में मूल आकृति जैसी दिखती है। अतः आकृति (i) में क्रम 4 की घूर्णन सममिति होगी।

जब आकृति (ii) को अंकित बिन्दु के परितः घुमाया जाता है, तो यह आकृति तीन स्थितियों (120°, 240° और 360°) में | मूल आकृति जैसी दिखती है। अतः आकृति (ii) में क्रम 3 की घूर्णन सममिति होगी।

जब आकृति (iii) को अंकित बिन्दु के परितः घुमाया जाता है, तो यह आकृति दो स्थितियों (180° और 360°) में मूल आकृति जैसी दिखती है। अतः आकृति (iii) में क्रम 2 की घूर्णन सममिति होगी।

पाठ्य-पुस्तक पृष्ठ संख्या # 290

MP Board Class 7th Maths Solutions

MP Board Class 7th Maths Solutions Chapter 13 घातांक और घात Ex 13.3

MP Board Class 7th Maths Solutions Chapter 13 घातांक और घात Ex 13.3

प्रश्न 1.
निम्नलिखित संख्याओं को प्रसारित रूप में लिखिए :
279404, 3006194, 2806196, 120719, 20068
हल:
(i) 279404
= 2 × 100000 + 7 × 10000 + 9 × 1000
+ 4 × 100 + 0 × 10 + 4 × 1
= 2 × 105 + 7 × 104 + 9 × 103 + 4 × 102
+ 0 × 101 + 4 × 100

(ii) 3006194
= 3 × 1000000 + 0 × 100000 + 0 × 10000
+ 6 × 1000 + 1 × 100 + 9 × 10 + 4 × 1
= 3 × 106 + 0 × 105 + 0 × 104 + 6 × 103
+ 1 × 102 + 9 × 101 + 4 × 100

(ii) 2806196
= 2 × 1000000 + 8 × 100000 + 0 × 10000
+ 6 × 1000 + 1 × 100 + 9 × 10 + 6 × 1
= 2 × 106 + 8 × 105 + 0 × 104 + 6 × 103
+ 1 × 102 + 9 × 101 + 6 × 100

(iv) 120719
= 1 × 100000 + 2 × 10000 + 0 × 1000
+ 7 × 100 + 1 × 10 + 9 × 1
= 1 × 105 + 2 × 104 + 0 × 103 + 7 × 102
+ 1 × 101 + 9 × 100

(v) 20068
= 2 × 10000 + 0 × 1000 + 0 × 100
+ 6 × 10 + 8 × 1 = 2 × 104 + 0 × 103 + 0 × 102
+ 6 × 101 + 8 × 100

MP Board Solutions

प्रश्न 2.
निम्नलिखित प्रसारित रूपों में से प्रत्येक के लिए संख्या ज्ञात कीजिए:
(a) 8 × 104 + 6 × 103 + 0 × 102 + 4 × 101 + 5 × 100
(b) 4 × 105 + 5 × 103 + 3 × 102 + 2 × 100
(c) 3 × 104 + 7 × 102 + 5 × 100
(d) 9 × 105 + 2 × 102 + 3 × 101
हल:
(a) 8 × 104 + 6 × 103 + 0 × 102 + 4 × 101 + 5 × 100
= 8 × 10000 + 6 × 1000 + 0 × 100 +4 × 10 + 5 × 1
= 80000 + 6000 + 0 + 40 + 5
= 86045

(b) 4 × 105 + 5 × 103 + 3 × 102 + 2 × 100
= 4 × 100000 + 5 × 1000 + 3 × 100 + 2 × 1
= 400000 + 5000 + 300 + 2
= 405302

(c) 3 × 104 + 7 × 102 + 5 × 100
= 3 × 10000 + 7 × 100 + 5 × 1
= 30000 + 700 + 5
= 30705

(d) 9 × 105 + 2 × 102 + 3 × 101
= 9 × 100000 + 2 × 100 + 3 × 10
= 900000 + 200 + 30
= 900230

प्रश्न 3.
निम्नलिखित संख्याओं को मानक रूप में व्यक्त कीजिए:
(i) 5,00,00,000
(ii) 70,00,000
(iii) 3,18,65,00,000
(iv) 3,90,878
(v) 39087.8
(vi) 3908.78
हल:
(i) 5,00,00,000 = 5 × 10000000
= 5 × 107

(ii) 70,00,000 = 7 × 1000000
= 7 × 106

(iii) 3,18,65,00,000 = 3.186500000 × 109
= 3.1865 × 109

(iv) 3,90,878 = 3.90878 × 105

(v) 39087.8 = 3.90878 × 104

(vi) 3908.78 = 3.90878 × 103

MP Board Solutions

प्रश्न 4.
निम्नलिखित कथनों में प्रकट होने वाली (आने वाली) संख्याओं को मानक रूप में व्यक्त कीजिए:
(a) पृथ्वी और चन्द्रमा के बीच की दूरी 3,84,000,000 m है।
(b) निर्वात स्थान में प्रकाश की चाल (या वेग) 3,00,000,000 m/sec है।
(c) पृथ्वी का व्यास 1,27,56,000 m है।
(d) सूर्य का व्यास 1,400,000,000 m है।
(e) एक आकाशगंगा में औसतन 100,000,000,000 तारे हैं।
(f) विश्व मण्डल (या सौर मण्डल) 12,000,000,000 वर्ष पुराना है।
(g) आकाशगंगा के मध्य से सूर्य की दूरी 300,000,000,000,000,000,000 m आंकलित की गई है।
(h) 1.8 g भार वाली पानी की एक बूंद में 60,230,000,000,000,000,000,000 अणु (molecules) होते हैं।
(i) पृथ्वी में 1,353,000,000 km3 समुद्र जल है।
(j) मार्च 2001 में भारत की जनसंख्या 1,027,000,000 थी।
हल:
(a) पृथ्वी और चन्द्रमा के बीच की दूरी
= 3,84,000,000 m
= 3.84000,000 × 108 = 3.84 m × 108 m

(b) निर्वात स्थान में प्रकाश की चाल
= 3.00,000,000 m/sec = 3 × 108 m/sec

(c) पृथ्वी का व्यास = 12756000 m
= 1.2756000 × 107 m = 1.2756 × 107 m

(d) सूर्य का व्यास = 1,400,000,000m
= 1.400,000,000 × 109 m
= 1.4 × 109 m

(e) एक आकाशगंगा में औसतन तारे
= 1,00.000.000,000 = 1 × 1011

(f) विश्वमण्डल पुराना है = 12,000,000,000
= 1.2 × 1010 वर्ष

(g) आकाश गंगा से सूर्य की दूरी
= 300,000,000,000,000,000,000 m
= 3 × 1020 m

(h) 1.8g भार वाली पानी की बँद में अण
= 60,230,000,000,000,000,000,000
= 6.023 × 1022

(i) पृथ्वी में समुद्र जल
= 1,353,000,000 km3
= 1.353 × 109 km3

(j) मार्च 2001 में भारत की जनसंख्या
= 1,027,000,000 = 1.027 × 109

MP Board Class 7th Maths Solutions