Physical Chemistry — 6 Physics PYQs with Answers | UKPSC PYQ Hub

Question 1

pH value of water is?

Accepted Answer

About 7. pH value of water is about 7. pH is a measure of how acidic/basic water is. The range goes from 0 to 14, with 7 being neutral. pH of less than 7 indicate acidity, whereas a pH of greater than 7 indicates a base. The pH of water is a very important measurement concerning water quality.

Question 2

A radioactive element whose large deposits are found in India is?

Accepted Answer

Thorium. India has largest deposit of Thorium in world. It accounts nearly 25 percent reserve of the world. Kerala, Jharkhand, Bihar, Tamil Nadu and Rajasthan are the main producers.

Question 3

Stars produce their energy through which of the following process?

Accepted Answer

Nuclear Fusion. Stars produce their energy through nuclear fusion. In the process of nuclear fusion, when two light nuclei fuse to form a larger nucleus, energy is released. In star hydrogen nuclei combine together to form helium nuclei and during in this process energy release

Question 4

When ice melts, its volume

Accepted Answer

Decreases. When ice melts, it becomes denser (0ºC to 4°C) due to which its volume decreases. This means that water has its highest density and smallest volume at 4°C

Question 5

Plants add water to the atmosphere in process called

Accepted Answer

Evapotranspiration. Evapotranspiration is a combined process by which water moves from the Earth's surface into the atmosphere. It covers evaporation and transpiration.

Question 6

Which of the following is pure and free from impurities?

Accepted Answer

Distilled water. Distilled water is water free from impurities which many impurities are removed by distillation. It is not suitable for drinking because it lacks the salts necessary for life. It is used for medical purpose and in making medicines.