Importance of Water

Q.

On what factor does the magnitude of the surface tension of a liquid depend?

Q.

When there are no external forces, the shape of a liquid drop is determined by

1. the heat capacity of the liquid

2. the boiling point of the liquid

3. the freezing point of the liquid

4. the surface tension of the liquid

Q. The process in which clouds get heavy and result into rain is known as .

1. condensation
2. saturation
3. precipitation
4. evaporation

Q.

Which phenomenon is responsible for the spherical shape of liquid drops?

Q.

Why is water droplets seen in spherical shape ?

Q.

Write 4 ways to conserve water

Q. Borewells are used to extract .

1. wastewater
2. rainwater
3. surface water
4. groundwater

Q.

State the ways to reduce water consumption at homes.

Q. percent of Earth's surface is covered with water.

1. Thirty two
2. Seventy one
3. Ninety seven
4. Forty five

Q. Question 6
On placing an inverted tumbler over a burning candle, the flame extinguishes after some time. This is because of non availability of

(a) Oxygen
(b) Water vapours
(c) Carbon dioxide
(d) Was covered with tumbler

Q.

Describe the different zones of a candle flame.

Q. The early civilisations were built near rivers for:

1. cultivation
2. drinking purposes
3. domestic uses
4. hunting and fishing

Q. if there is fire on petrol pump why we does not use water to reduce it ?

Q.

Describe the different zones of a candle flame.

Q.

Untreated sewage is discharged into the rivers. How will it affect the population of aquatic animals in the river?

1. Water table decreases

2. Water table increases

3. Water table is not dependent on population

4. Water table will niether increase nor decrease

Q. Clear, transparent water is always fit for drinking. Comment.​ [2 marks]

Q.

Describe the different zones of a candle flame.

Q. The purest form of natural water is?

1. sea water
2. river water
3. rain water
4. lake water

Q.

Explain why a drop of liquid under external force is always spherical in shape.