Our Environment

21 solved questions from Class 10 Science, each with the full working. Tap any question to see the step-by-step solution.

1 Which of the following gases contributes most to the greenhouse effect? easy MCQ 1 mark Greenhouse gases
2 A factory emitted 1200 tonnes of CO₂ in 2018. After installing a scrubber, emissions reduced by 15% each year. What will be the total emissions in 2021? Round to the nearest tonne. hard 5 marks Quantitative reduction of pollutants
3 Which type of pollution results from the disposal of solid waste directly into rivers? medium MCQ 2 marks Water pollution
4 An Indian town generates 500 kg of solid waste per day. A new segregation and composting program reduces the amount of waste sent to landfill by 10% each year. What is the amount of waste that will be sent to landfill at the end of 3 years? Round to the nearest kilogram. medium 2 marks Percentage reduction in solid waste
5 Which of the following is the main source of noise pollution in Indian urban areas? easy MCQ 1 mark Noise pollution source
6 Which of the following gases has the highest global warming potential (GWP) over a 20‑year time horizon? medium MCQ 2 marks Greenhouse gases potency
7 In most Indian cities, which of the following contributes the most to noise pollution? easy MCQ 1 mark Source of noise pollution
8 List two simple actions that a typical Indian household can take to conserve water during daily chores. medium 2 marks Water conservation at home
9 In a grassland ecosystem, 20,000 J of solar energy falls on green plants. Calculate the amount of energy transferred to the tertiary consumer in this food chain. medium 3 marks Ten percent law of energy transfer
10 Pesticides were sprayed in a lake to control mosquitoes. The food chain in this lake comprises phytoplankton, small fish, hawk, and large fish. Arrange these organisms into a correct food chain and state which organism will have the maximum concentration of pesticides in its body. Give a reason for your answer. hard 3 marks Biological magnification in food chains
11 Which synthetic chemical compound is primarily responsible for the depletion of the ozone layer in the stratosphere? easy MCQ 1 mark Depletion of the ozone layer
12 Differentiate between biodegradable and non-biodegradable substances. Provide two examples of each. easy 2 marks Biodegradable and non-biodegradable wastes
13 What are decomposers? Explain two vital functions performed by decomposers in an ecosystem, and describe the consequences if decomposers were completely absent from the Earth. hard 5 marks Role of decomposers in an ecosystem
14 Compare the global warming potential (GWP) of methane (CH₄) and nitrous oxide (N₂O) over a 100‑year time horizon. State which gas has the higher GWP, give their approximate GWP values, and mention one major anthropogenic source for each gas. hard 4 marks GWP comparison of greenhouse gases
15 Which of the following is a non‑point source of water pollution? easy MCQ 1 mark Point vs non‑point water pollution sources
16 Define eutrophication. Mention any two adverse effects it can cause in a freshwater lake. medium 2 marks Eutrophication definition and impacts
17 Which of the following activities contributes the most to air pollution in Indian urban areas? easy MCQ 1 mark Major source of urban air pollution
18 What is the primary topic or theoretical principle explored in 'Our Environment' (Class 10 SCIENCE)? medium MCQ Chapter Core Principle
19 Which key mechanism or analytical rule is highlighted in 'Our Environment'? medium MCQ Key Analytical Mechanism
20 An Indian town generates 500 kg of solid waste per day. A new segregation and composting programme reduces the amount of waste sent to landfill by 10% each year. What is the amount of waste that will be sent to landfill at the end of 3 years? Round to the nearest kilogram. medium 3 marks Reduction in landfill waste
21 Explain three major causes of soil erosion in Indian agricultural fields and suggest one preventive measure for each cause. medium 3 marks Soil erosion causes and prevention