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Explain the harmful effects of ozone depletion on Earth
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1
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528
|
April 4, 2019
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(a) Why should ozone layer be protected to save the environment?
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1
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5247
|
April 4, 2019
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Give reason to justify the following: (a) The existence of decomposers is essential in a biosphere
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1
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5764
|
April 4, 2019
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“Energy flow in a food chain is unidirectional. Justify this statement
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1
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1029
|
April 4, 2019
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“Our food grains such as wheat and rice, the vegetables and fruits
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1
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981
|
April 4, 2019
|
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(a) What is an ecosystem? List its two main components
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1
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1051
|
April 4, 2019
|
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How is ozone formed in the higher level of atmosphere?
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1
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2812
|
April 4, 2019
|
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What is “Green House Effect”? State two advantages and two disadvantage of this effect
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1
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581
|
April 4, 2019
|
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“Reuse is better than recycling of materials”. Give reason to justify this statement
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1
|
1600
|
April 4, 2019
|
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List two reasons to show that the existence of decomposers is essential in an ecosystem
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1
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2351
|
April 4, 2019
|
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Why is Government of India imposing a ban on the use of polythene bags?
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1
|
901
|
April 4, 2019
|
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List the products of combustion of fossil fuels ? What are their adverse effects on the environment?
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1
|
731
|
April 4, 2019
|
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An environmentalist on visit to your school suggested the use of three R’s to save the environment
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1
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2428
|
April 4, 2019
|
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How are the following caused and what is the effect of each of them on our environment? (i) Depletion of ozone layer (ii) Acid rain
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1
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630
|
April 4, 2019
|
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List any four practices which help in protecting our environment
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1
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1146
|
April 4, 2019
|
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Why is conservation of wildlife considered important for us? Give any two reasons
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|
1
|
944
|
April 4, 2019
|
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What is acid rain? Mention its two harmful effects
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1
|
1253
|
April 4, 2019
|
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Distinguish between biodegradable and non-biodegradable wastes. Give one example of each
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1
|
540
|
April 4, 2019
|
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How does depletion of soil takes place? Suggest two ways to prevent it
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1
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573
|
April 4, 2019
|
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Describe how green house effect may cause atmospheric heating?
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1
|
508
|
April 4, 2019
|
|
Waste of which of the following two materials in more polluting? Polythene or paper. Give reasons for your answer
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1
|
1395
|
April 4, 2019
|
|
Write one negative effect, on the environment of affluent lifestyle of few persons of a society?
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1
|
929
|
April 4, 2019
|
|
The depletion of ozone layer is a cause of concern why?
|
|
1
|
1896
|
April 4, 2019
|
|
Why should biodegradable and non-biodegradable wastes be discarded in two separate dust bins?
|
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1
|
1087
|
April 4, 2019
|
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What is biomass? What can be done to obtain bio-energy using biomass?
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1
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2499
|
April 4, 2019
|
|
(i) What is biogas? Name two main combustible components of biogas?
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1
|
1371
|
April 4, 2019
|
|
(a) Name the device used to convert: 1. Solar energy into heat
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1
|
573
|
April 4, 2019
|
|
Compare and contrast bio-mass and hydro-electricity as source of energy
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1
|
756
|
April 4, 2019
|
|
1. What is a ‘solar cell’?
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1
|
611
|
April 4, 2019
|
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1. State one limitation of solar energy available from solar cells
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1
|
793
|
April 4, 2019
|