Important Questions Test: Water - UPSC MCQ

Water is a compound consisting of hydrogen and oxygen in fixed ratio.

The process of changing water into water vapour is called condensation.

Rain is also known as precipitation.

Water is not blue in colour.

Water is colorless because all light (except tiny bit of blue) is reflected back. 

Transpiration is the process by which moisture is carried through plants from roots to small pores on the underside of leaves, where it changes to vapor and is released to the atmosphere. Transpiration is essentially evaporation of water from plant leaves. Transpiration also cools plants, changes osmotic pressure of cells and enables mass flow of mineral nutrients and water from roots to shoots.
Therefore, the correct answer is option A.

The purest form of water is rain water as no impurities is present in it.But when it comes to earth, the gases present in the atmosphere gets mixed with it and hence makes it impure but rainwater is pure when it fells from clouds.

Well is underground source of water while river, lake and sea are surface source of water.

The gaseous state of water is vapour form by evaporation or boiling the water.

The thick envelop of air around the earth is called atmosphere, which contain nitrogen and oxygen gas mainly.

Water is the only substance, which is found in all three states in nature.