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Class 8th Sample Papers Science

SCIENCE TEST CLASS VIII NCERT on Friction

SCIENCE TEST CLASS VIII

TIME: – 1HR                                                                                                    F.M.:- 50

              TOPICS: - Friction,  Microorganisms: Friend and Foe                                   

 

Q1. Each question carries 1mark.

  1. a. Microorganisms are classified into four major groups. Name
  2. Several diseases like tuberculosis, smallpox and hepatitis can be prevented by
  3. Define Friction
  4. Friction depends on the ?
  5. Give two ways to increase friction?
  6. What is atmospheric pressure?

Q2. Each question carries 2marks.

  1. Write short notes on   A. Protozoa            B. Algae
  2. Define the process of fermentation and its
  3. Write short notes on medicinal use of
  4. Find the net force acting on an object whose mass is 2 kg, as shown

5. Explain why sliding friction is less than static

Q3. Each question carries 3marks.

  1. What are the major precautions one should follow while taking antibiotics?
  2. Explain how microbes are useful to us in our day to day
  3. Explain increasing and reducing
  4. Write and explain the effect of forces.
  5. What is fluid friction? Write the factors on which fluid friction
  6. Explain why objects moving in fluids must have special

Q4. Each question carries 5marks.

  1. What are the major group of microorganisms explain each group with their harmful and useful effects in our life?   5
  2. Write and explain types of Forces ? 3
    Find the Force in dyne acting on a body of mass 10 kg and an acceleration of 8m/s2 3
  3. Explain the reason. 2+1+1+1
    a.  Force of friction increases when two surfaces are pressed
    b. While travelling on a rickshaw, you might have experienced that if the seat cover is very smooth, you tend to slip when brakes are applied
    c. The handle of a cricket bat or a badminton racquet is usually
    d. Give examples to show that friction is both a friend and Foe?
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Class 8th Geography

Mineral and Power Resources :Geography For Class 8th NCERT

Minerals :

  • Minerals are non-living solid substances which are concentrated in a particular area or rock formations.
  • These natural substances found in nature that have a definite chemical composition is called minerals.

Properties Of Mineral

  • They are unevenly distributed over the earth’s surface.
  • They are mixed up with a large variety of impurities.
  • The mineral resources are exhaustible

Types of Mineral

On the basis of composition, minerals are broadly classified into metallic and non-metallic.

EXTRACTION OF MINERALS

  • The method of taking out minerals from rocks buried under the earth’s surface is called mining.
  • The method used for mining depends upon the depth at which the minerals are located.
  1. Quarrying– Minerals present near the surface of the earth are simply dug out is called

  1. Open Cast mining-. Minerals present at shallow depth can be taken out by removing the surface layer. It is one of the easiest and cheapest methods of extracting minerals.
  2. Shaft Mining- To extract minerals which are present at great depths, a deep hole or shaft is dug. It is known as shaft mining.

shaft mining

  1. Drilling- Deep wells are bored to obtain mineral oil like petroleum, and natural gas which occur far below the earth’s surface by the process called drilling.

Distribution of minerals in different continents

  • Asia- The important minerals found are iron ore, tin, manganese, bauxite, nickel, copper, zinc, lead, antimony, mica and tungsten.
  • China, India, Russia, Azerbaijan and southeast Asia have rich deposits of iron ore.
  • India and Indonesia are the main producers of bauxite.
  • Asia produces more than half of the world’s tin.
  • The leading producers are China, Malaysia, Thailand, Vietnam, Philippines and Indonesia.
  • India is the largest producer of mica in the world.
  • China is the leading producer of lead, antimony and tungsten.
  • Asia also has rich commercial deposits of manganese, nickel, copper, gold, silver and zinc.

Europe-

  • The main producers of Iron is Ukraine, Russia, Spain, Germany, France. Sweden and UK.
  • Germany, France, Norway, Austria, UK. Russia and Italy are main producers of Bauxite.
  • Eastern Europe and Russia have deposits of copper, manganese and nickel.

North America

  • USA is the second-largest producer of iron ore in the world
  • The largest deposits of lead and zinc are found in British Columbia in Canada.
  • Mexico is the largest producer of silver in the world.

South America

  • Brazil is the largest producer of iron ore in the world
  • Nitrates, used in the making of chemical fertilizers, are found in the Atacama desert
  • Brazil and Bolivia are major producers of tin in the world

Africa

  • Congo is the largest producer of cobalt.
  • Diamonds are mostly found in Kimberley in South Africa
  • Gold is mined in South Africa, Zimbabwe and Congo

Australia

  • Australia is the largest producer of bauxite in the world.
  • Rich deposits of gold, diamond, iron ore, tin and nickel are also mined.
  • Gold deposits are mostly found in Kalgoorlie and Coolgardie.

Mineral and Energy Resources :NCERT Geography Lesson For class 10th

Antarctica

  • Due to large deposits of ice cover it is very difficult to mine minerals in this region
  • It is believed that there are reserves of coal, iron ore, copper, uranium, gold and silver.

Distribution of minerals in India

Metallic Minerals 

Pic Courtesy mapsofindia,com

 

C:\Users\admin\Documents\metallic mineral india.png

Non- Metallic Minerals 

Pic Courtesy mapsofindia,com

non metallic mineral india.png

CONSERVATION OF MINERALS

  • Minerals are non-renewable resources.
  • Their rate of formation is slow as compared to the rate at that they are getting used.
  • it’s completely necessary to use these resources judiciously, with minimum wastage
  • recycling of metals is another way of conserving our mineral resources

POWER RESOURCES

  • Power is needed for the growth and development of agriculture, industry, transport and communication.
  • Their distribution is highly uneven as some places have many resources and few are not.

Food:Where Does It Come From For Class 6th NCERT Science

The power resources are of two types—

  1. conventional and Non-Conventional Power Resources
  • Conventional sources of energy are those which have been in common use for a long time.
  • These are Usually exhaustible sources of energy.
  • Exhaustible sources or non-renewable sources are the sources of energy which cannot be replenished in a shot\rt time and take millions of years.
  • Example-Coal, petroleum and natural gas are formed from fossils and hence are called fossil fuels
  • Hydel power is also a conventional source of energy, but it is non-exhaustible
  1. Coal –

  • Coal was the basis for the Industrial Revolution in Europe.
  • It occurs in layers of varying thickness in sedimentary rocks.
  • The four varieties of coal are peat, lignite, bituminous and anthracite.
  • It is the major source for thermal electricity.

coal-types.uses.jpg

Petroleum

  • Petroleum (in Latin petra means rock and oleum means oil) is also known as rock oil or crude oil.
  • Petroleum or mineral oil is derived from organic materials trapped in the layers of sedimentary rocks
  • Majority of world’s petroleum is found in Gulf countries
  • The major petroleum rich countries are Saudi Arabia, Iran, Iraq, Kuwait, United Arab Emirates (UAE), Qatar and Bahrain
  • In India oil is found in Digboi (Assam), Gujarat, off the coast of Mumbai and in Godavari and Krishna river basin.

Natural Gas –

  • Natural gas can be found in association with petroleum, or it may occur alone.
  • because of undeveloped technology in the past major natural gases were escaped or burnt without using it properly
  • The main producing areas are Mumbai High, Gujarat, Assam, Tamil Nadu and Tripura.

Hydroelectric power-

  • In hydro electric power electricity is produced using the potential energy of water falling from height by using dams.
  • The falling water is channelized to enter a turbine and the moving blades turn the generator to produce electricity.
  • The water coming out of the turbine is used for irrigation
  • In India some of the major multi purpose dams are of them are Bhakra, Nangal, Hirakud, Damodar Valley Corporation, Nagarjuna Sagar, Kosi, Koyna, Rihand and Narmada valley.

Advantages Disadvantages
  • it is renewable source of energy
  • The generated electricity is cheap
  • It causes limited pollution
  • Dams are expensive to build
  • some time it becomes major reason for flooding and earth quake
  • Electricity can’t be stored once produced

Nuclear Energy

  • The use of this technology to produce electricity started in the 60s.
  • Nuclear power is obtained by altering the structure of atoms.
  • When such an alteration is made, energy is released in the form of heat.
  • The heat energy is used to produce electricity.
  • The main nuclear power generating stations are at Tarapur, Kalpakkam, Rawatbhata

Non-conventional Sources of Energy

  • With increase in the demand for energy and fast depletion of conventional energy sources
  • The non-conventional sources of energy are gaining importance.

Solar Energy

  • The sun is the source of all energy on the earth.
  • In the tropical region solar energy is widely available.
  • But it has not been fully developed due to lack of available technology.
  • Photovoltaic cells convert sunlight directly into electricity.
  • The cost involved in installing and maintaining solar energy equipment is high.
  • Also its use is limited by clouds and at night.

Wind Energy

  • It is also an inexhaustible source of energy.
  • The wind blows onto the wind turbines and rotates them
  • Wind turbines can be most efficient in areas with high and regular wind speeds such as exposed coast or upland areas.
  • Tamil Nadu, Maharashtra, Gujarat, Karnataka and Rajasthan are major produces of wind energy .

Advantages Disadvantages
  • It is Non-Polluting
  • After the Initial Expense ,Relative cost becomes less
Winds donot blow all the time so,production and storing is difficult

WInd farms are noisy and disturb the TV and Radio reception


Geothermal Energy

  • The energy derived from hot springs, emission of dry or wet steam from hot rocks at great depths is called geothermal energy.
  • In India, the potential sites for generating geothermal energy are Puga Valley (Ladakh), Tatapani (Odisha), Tuwa (Gujarat) and Jalgaon, Unai (Maharashtra).

Tidal Energy

  • The rise and fall of sea water in coastal areas are called tides
  • Blades of turbine are turned by the tides to produce electricity.
  • Gulf of Kutch in India has huge tidal barrages

Bio-gas

  • Organic wastes, especially human and animal wastes, cow dung, dead plants and kitchen wastes are converted into gaseous fuel called Biogas
  • India is the leader in the development of this technology.

Conservation of Mineral and Natural Resources

  • The following steps are useful in conserving minerals and power resources.
  • Efficient utilization of resources
  • Improvement in the techniques of extraction and purification
  • Recycling of resources
  • Saving mines from collapsing
  • Use of alternative energy resources
    Implementing above steps could  conservation of minerals and power resources will ensure a better economy for future generations.
Categories
Class 8th Science

SCIENCE Test for Class 8th Science:Friction ,Micro Organisms

SCIENCE CLASS VIII

TIME: – 1HR                                       F.M.:- 25

TOPICS: –
Friction
Microorganisms: Friend and Foe

Q1. Each question carries 1mark.
(i) 
Microorganisms are classified into four major groups. Name them.
(ii)  Several diseases like tuberculosis, smallpox and hepatitis can be prevented by ___________.
(iii) Define pasteurization.
(iv) Friction depends on the ________ of surfaces.
(v)  Give two ways to increase friction?

Q2. Each question carries 2marks.
(i)
Write short notes on           A. Protozoa            B. Algae
(ii) Define the process of fermentation and its application.
(iii) Write short notes on medicinal use of microorganisms.
(iv) Find the net force acting on an object whose mass is 2 kg, as shown in figure.
(v) Explain why sliding friction is less than static friction.

Q3. Each question carries 3marks.
(i) What are the major precautions one should follow while taking antibiotics?
(ii) Explain how microbes are useful to us in our day to day life.
(iii) Explain increasing and reducing friction.
(iv) What is fluid friction? Write the factors on which fluid friction depends.
(v) Explain why objects moving in fluids must have special shapes.

Q4. Each question carries 5marks.
(i)
  What are the major group of microorganisms explain each group with their harmful and useful effects in our life?
(ii) Explain nitrogen cycle with a diagram.
(iii) Explain the reason.  2+2+1
A.  Force of friction increases when two surfaces are pressed harder.
B. While travelling on a rickshaw, you might have experienced that if the seat cover is very smooth, you tend to slip when brakes are applied suddenly.
C. The handle of a cricket bat or a badminton racquet is usually rough.
(iv) Give examples to show that friction is both a friend and foe.

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Categories
Class 8th Sample Papers Science

Science Test For Class 8th Metals and Non-metals

                                                         SCIENCE TEST – I

CLASS VIII

TIME: – 1.5HR                                          F.M.:- 50

Topic-
Metals And Non Metals
Force and Pressure
Chemical Effect of Electric Current

Q1. Each question carries 1mark.

(i) Name some materials which are good conductors of electricity.

(ii) The path through which an electric current flows is called

  1. Electric path b. Electric relay              c. Short circuit               d. Electric circuit

(iii) How chlorination is done to purify water?

(iv) Fuel must be heated to its_________________ before it starts burning.

(v) Name the gases involved in acid rain.

Q2. Each question carries 2marks.

(i) In an experiment 3.5 kg of a fuel was completely burnt. The heat produced was measures to be 160,000 kj. Calculate the calorific value of the fuel.

(ii) Explain why it is difficult to burn a heap of green leaves but we can easily burn dry leaves?

(iii) What do you mean by marble cancer?

(iv) How smog is harmful to us?

(v) It is said that rain water is as pure as distilled water, but once while testing rain water compass needle shows deflection, explain why?

Q3. Each question carries 3marks.

(i) Write short notes on greenhouse gases.

(ii) Explain the process of electroplating.

(iii) What do you mean by electrolysis and electrolytes?

(iv) Explain why the process of rusting can be called as slow combustion.

(v) Explain with an activity that air is necessary for combustion.

Q4. Each question carries 5marks.

(i) Explain the process of electroplating, along with its advantages and uses.

(ii) Clear transparent water is always fit for drinking, do you agree? Explain your answer.

(iii) Explain air pollution and its harmful effects. Also list some important measures to reduce air pollution.

(iv) Explain how combustion takes place in a matchstick.

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Categories
Class 8th Sample Papers Science

Science Test for Class 8th

SCIENCE TEST – II
CLASS VIII
TIME: – 1.5HR F.M.:- 50

TOPICS: –
Reaching the age of Adolescence
Reproduction in Animals
Synthetic Fibres and Plastics.

Q1. Each question carries 1mark.

(i) What are exocrine glands?
(ii) Growth hormone is secreted by ________________ gland.
(iii) Which kind of capability does frog gain by transforming from tadpole to adult frog?
(iv) Give examples of some oviparous and viviparous animals.
(v) Cellulose is made up of large number of___________________ units.

Q2. Each question carries 2marks.

(i) What is the relation between adolescence and puberty?
(ii) Define secondary sexual characters.
(iii) Differentiate between zygote and foetus.
(iv) Why we prefer plastic containers for storage of items like water, milk, pickles, dry food? (v) Differentiate between natural and artificial fibres.

Q3. Each question carries 3marks.

(i) What is the cause of
A. Diabetes     B. Goitre        C. AIDS
(ii) Write short notes on
A. increase in height during puberty.
B. changes in body shape during puberty.
C. voice change at puberty.
(iii) Why frog lays egg coverless, whereas, Hen lays it with hard cover? Explain.
(iv) What are the advantages of artificial silk over natural silk? (v) State the source of following fibres
A. Cotton B. Rayon C. Nylon

Q4. Each question carries 5marks.

(i) A. Explain the process of sexual reproduction in human beings.
B. Name different stages of the lifecycle of a frog and silkworm.
(ii) Draw labeled diagram of male and female reproduction system.
(iii) What are synthetic fibres and its various types?
(iv) Explain secondary sexual characters and roles of hormones in initiating reproductive function.

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Free Course For NCERT Class 8 Science

 

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Class 8th Sample Papers

Comparing Quantities Sample test for Class 8th Mathematics

Sample test on Mathematics for class 8th

Topic – Comparing quantities, Direct and inverse Proportion

1.Convert 4:7 into percent       1 
2. An alloy contains Copper, Silver and Gold in the ratio 5:10:12. If the total weight of the alloy is 54 Kg . Find the quantity of Gold in kg.      2
3. Sreyanshee Sold her cycle at 15 % loss. Had she sold it for rupees 240 more, she would have gained 10%. find the cost price of the cell phone.     3
4. Selling Price of 4 bananas is cost price of 6 bananas. Find the profit/Loss %.     2
5. Find the single discount equal to two successive discounts of 20%.    2
6. What price a shopkeeper should mark on an article that cost him 600 to gain 20 % after allowing a discount of 10 %.      3
7. The population of a city was 422500 in the year 2010. If it increases at the rate of 4 % per annum. Find the population of the town in 2012.      3
8. Swoyanshree can finish a work in 4 days while akshit can finish the same work in 10 days. How long will they take to complete the work, if both of them work together?       3
9. A,B,and C can do a work in 12 days ,15 days and 20 days respectively. They started working together, but after 4 days A left. In how many days will B and C complete the work?      4
10. A fort has enough food for 720 soldiers for 35 days. If after 5 days, 120 soldiers left the fort, How long will the food last now?     4
11. A Swimming pool can be filled in 4 hours by 8 pumps of the same type.How many such pumps are required if the pool is to be filled in 8/3 hours .    3
12. Somu types 108 words in 6 minutes. How many metres can be bought for rupees 2250.     3
13. Shabnam takes 20 minutes to reach her school, If she goes at a speed of 6 km/hr. If she wants to reach school in 24 minutes, What should be her speed? 3
14. Calculate the compound interest on Rupees 8400 for 1 year at the rate of 10% per annum Compounded half-yearly?      4

NCERT Solutions For Class 8th

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Class 8th History Sample Papers

The Revolt of 1857: Short Questions For Class 8th History

The Revolt of 1857 Questions for Class 8th

  1. The Revolt against the British started in the year ______
  2. The Revolt started in which city.
  3. Who led the revolt in Awadh?
  4. What was Wahabi movement?
  5. Who was the last Mughal Emperor?
  6. Under whose command did the British army defeat the rebels in Lucknow?
  7. What the Bengal tenancy act of 1859 tried to ensure?
  8. What is Patriotism?
  9. The Revolt in Kanpur was led by whom?
  10. What was the official language in Bengal ,before English became the Official language?
  11. What is Doctrine of Lapse?
  12. Name any four places which were the main centers of Revolt?
  13. Who was the commander of Nana Saheb?
  14. Who became the viceroy of India after the revolt ?
  15. What is Nationalism?

Free Test for Social Science Class 10th NCERT

Civil Disobedience Movement and Peoples Participation Class 10th History

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Class 8th

Topic Wise Science Sample Test for Class 8th

The Questions are based on NCERT Syllabus 

Topics Covered : 

  1. Chemical effects of Electric Current
  2. Combustion of Flame 

                   

     SCIENCE TEST – I    For Class 8th F.M.:- 50

Q1. Each question carries 1mark.

(i) Name some materials which are good conductors of electricity.

(ii) The path through which an electric current flows is called

  1. Electric path b. Electric relay              c. Short circuit               d. Electric circuit

(iii) How chlorination is done to purify water?

(iv) Fuel must be heated to its_________________ before it starts burning.

(v) Name the gases involved in acid rain.

Q2. Each question carries 2marks.

(i) In an experiment 3.5 kg of a fuel was completely burnt. The heat produced was measures to be 160,000 kj. Calculate the calorific value of the fuel.

(ii) Explain why it is difficult to burn a heap of green leaves but we can easily burn dry leaves?

(iii) What do you mean by marble cancer?

(iv) How smog is harmful to us?

(v) It is said that rain water is as pure as distilled water, but once while testing rain water compass needle shows deflection, explain why?

Q3. Each question carries 3marks.

(i) Write short notes on greenhouse gases.

(ii) Explain the process of electroplating.

(iii) What do you mean by electrolysis and electrolytes?

(iv) Explain why the process of rusting can be called as slow combustion.

(v) Explain with an activity that air is necessary for combustion.

Q4. Each question carries 5marks.

(i) Explain the process of electroplating, along with its advantages and uses.

(ii) Clear transparent water is always fit for drinking, do you agree? Explain your answer.

(iii) Explain air pollution and its harmful effects. Also list some important measures to reduce air pollution.

(iv) Explain how combustion takes place in a matchstick.

Ncert Solutions For Class 8th