Answer: Option C. -> Washing cars
:
C

Human beings need a certain amount of water for survival and maintenance of hygiene. But using this precious clean water to wash cars can be regarded as wastage of water especially during times of scarcity. We commonly see ourselves and our neighbours wasting tremendous quantities of water to wash cars which can also be cleaned using lesser quantity of water.
We should use methods which use less water. For example, we can use sprays instead of buckets to clean the car.

Answer: Option A. -> True
:
A

As we keep digging the surface of Earth, we will observe a level where all the spaces between the soil and rock particles is occupied by water. This water is called groundwater. Hence the above statement is correct.

Answer: Option B. -> False
:
B
Pumping out of water at a rate faster than its rate of replenishment leads to water depletion. Water depletion is more prominent in urban areas where excessive population, industrialisation and urbanisation put a strain on groundwater reserves. Hence, the above statement is incorrect.

Answer: Option A. -> 0.006%
:
A

Though 71% of the Earth's total surface is covered with water, it is largely in the form of oceans and seas. This water is salty and cannot be used for daily activities by humans. Only 2.5-2.75% is fresh water, including 1.75-2%, is frozen in glaciers, ice and snow, 0.5-0.75% as fresh groundwater and soil moisture, and less than 0.01% of it as surface water in lakes, swamps and rivers. And of this fresh water, the actual amount of water that is directly available and safe for use for humans, i.e., usable freshwater, is only around 0.006%.

Answer: Option A. -> Tube well
:
A

The water trapped in aquifers is commonly and most economically extracted using tube wells and hand pumps. For doing this, a hole has to be dug through the earth which reaches the aquifers through which water can be extracted.

Answer: Option D. -> 50 litres per person per day.
:
D

The United Nations has said that every person requires about 50 litres of water every day for their daily needs such as drinking, washing, cooking and maintaining proper hygiene. Though 50 litres of water does not seem like a lot of water yet billions of people all around the world do not have access to even half of this recommended quantity. Hence, there is an immediate need for spreading awareness about the conservation of water.

Answer: Option C. -> No, the situation will be in balance.
:
C

Water table reduces if we keep consuming groundwater. In a situation where the same amount of water that is being used gets infiltrated back to the ground naturally then the case of groundwater depletion does not arise. Hence, the situation will be in balance.

Answer: Option A. -> Uneven distribution of rain.
:
A

The uneven distribution of rainwater causes floods in one area while drought in the other. Some places have a good amount of rainfall and are water rich. Other places, like deserts have scanty rainfall. 
Excessive rain causes floods in some areas. Parts of Bihar and Uttar Pradesh are hit by floods almost every year during the rainy season. Whereas other places like Rajasthan have scanty rainfall and face drought. We should promote rainwater harvesting in areas which have low rainfall.

Answer: Option A. -> Use of drip irrigation
:
A and C
Water resource management involves planning, development, distribution and management of the optimum use of water resources.
Drip irrigation is a technique of watering plants by making use of narrow tubings which deliver water directly at the base of the plant. It is the most economical way to use water for irrigating the crops.
Bawris are one of the oldest methods of rain water harvesting. Bawris are deep wells dug in the ground which have steps to reach the water stored.
To save water we should avoid using taps that leak and should not keep the tap running while brushing.

Answer: Option A. -> Use of drip irrigation
:

The various forms of water are:
i) Solid - Ice
ii) Liquid - Water
iii) Gaseous - Water Vapour