CBSE Class 5 Environmental Studies Question Paper Set 02 with Solutions

Answer: (b) Sand. Salt, sugar and detergent dissolve in water, but sand does not dissolve and settles at the bottom.

Teacher's Note:
1. A soluble substance mixes completely with water and seems to disappear.
2. Remember sand and stones as common examples of insoluble things.

Answer: (b) Litre. Litre is the unit of volume of liquids; metre, kilometre and inch measure length or distance.

Teacher's Note:
1. Match the unit with what is measured: length uses metres, liquids use litres.
2. Do not confuse volume with length.

Answer: (b) Lever. A seesaw is a bar that rests and turns on a fixed point called the fulcrum.

Teacher's Note:
1. A lever always has a bar and a point to turn on.
2. Think of other levers such as scissors and a crowbar.

Answer: (c) Pesticides. Too much use of chemical pesticides harms the soil and the tiny living things in it.

Teacher's Note:
1. Manure is natural and improves soil, while strong chemicals can harm it.
2. Poor seeds affect the crop, not the soil.

Answer: True. Fossil fuels like coal and petrol will finish one day and they cause pollution.

Teacher's Note:
1. Fossil fuels took millions of years to form and cannot be made again quickly.
2. Using solar and wind energy more is a good answer to give.

Answer: True. Mt. Everest in the Himalayas is the highest mountain peak above sea level.

Teacher's Note:
1. Everest is in the Himalayas on the border of Nepal and Tibet.
2. Do not mix it up with the highest peak of India.

Answer: True. The spiral ridge of a screw is a slope (inclined plane) wound around a rod.

Teacher's Note:
1. If you could unwind the ridge of a screw, you would get a slope.
2. A screw helps to hold things together tightly.

Answer: Water. It exists as ice (solid), water (liquid) and steam (gas) in everyday conditions.

Teacher's Note:
1. Think of ice, water and water vapour.
2. Changing temperature changes the state of water.

Answer: Electricity (hydroelectricity). Falling water turns the turbines, which run generators.

Teacher's Note:
1. Moving water has energy that can turn a turbine.
2. This is a renewable source of energy.

Answer: Wedge. They have a thin sharp edge that cuts or splits things.

Teacher's Note:
1. A wedge is two inclined planes joined back to back.
2. The sharper the edge, the easier the cutting.

Answer: 1. A solution is a mixture made when a substance (solute) dissolves completely in a liquid (solvent).
2. Example: salt dissolved in water.

Teacher's Note:
1. A solution has two parts, the solute and the solvent.
2. Always add an example to earn full marks.

Answer: 1. Some gases in the air, such as carbon dioxide, trap the heat of the Sun near the Earth like the glass of a greenhouse.
2. This keeps the Earth warm, but too much of these gases makes the Earth hotter (global warming).

Teacher's Note:
1. Say that gases trap heat in the air around the Earth.
2. Mention that burning fuels adds to these gases.

Answer: 1. Simple machines are tools with few or no moving parts that make our work easier.
2. Examples: lever, pulley, wedge, screw, inclined plane and wheel and axle.

Teacher's Note:
1. They help us by reducing the effort we need to put in.
2. Name at least two examples.

Answer: 1. Water can dissolve a very large number of substances such as salt, sugar and many gases.
2. More substances dissolve in water than in any other liquid, so it is called the universal solvent.

Teacher's Note:
1. Universal means that it works for almost everything.
2. Do not say that water dissolves everything, because sand and oil do not dissolve.

Answer: 1. Soluble substances dissolve in water (for example, salt and sugar).
2. Insoluble substances do not dissolve in water (for example, sand and chalk powder).

Teacher's Note:
1. Give one example for each kind.
2. Insoluble things can be separated by filtering.

Answer: Biodegradable fuels come from plants and animals and can be broken down naturally:
1. Firewood
2. Cow dung cakes
3. Biogas (or charcoal, agricultural waste)

Teacher's Note:
1. Think of fuels that come from living things.
2. These fuels do not stay in nature for ever, unlike plastic.

Answer: 1. Renewable resources are those that can be used again and again or are replaced quickly in nature, for example sunlight, wind and water.
2. Non-renewable resources are limited and get used up, taking millions of years to form again, for example coal, petroleum and natural gas.
3. Renewable resources cause little pollution, while non-renewable fuels cause more pollution.

Teacher's Note:
1. Use examples from each side to make the answer strong.
2. The key word is replaced: renewable ones are, non-renewable ones are not.

Answer: 1. Manure is natural and is made from rotting plant and animal waste such as dung and leaves; fertiliser is made in factories from chemicals.
2. Manure adds humus and improves the soil; fertiliser gives nutrients quickly but does not add humus.
3. Manure is cheap and safe; too much fertiliser can harm the soil and pollute water.
4. Manure is used in large quantity and works slowly; fertiliser is needed in small quantity and works fast.

Teacher's Note:
1. Think natural versus man-made.
2. Four clear points are needed for four marks.