Heat and Energy Exe-6C Very Short Answer Concise Physics ICSE Class-9 Selina Publishers

Ans-

1. A source of energy should be safe and convenient to use.
2.  should be economical and easy to store and transport.

Q2- Select the renewable and non-renewable sources of energy from the following :

1- Coal
2-Wood
2- Water
4- Diesel
5- Wind
6- Oil

Ans- Renewable : Wood, Water and Wind

Non-renewable : Coal, Diesel and Oil

Q3- What is the main source of energy for the earth?

Ans- The Sun is the main source of energy for the earth.

Q4- State the energy transformation in the following :

(i) electricity is obtained from solar energy.

(ii) electricity is obtained from wind energy.

(iii) electricity is obtained from hydro energy.

(iv) electricity is obtained from nuclear energy.

Ans:  i. Light energy into electrical energy
ii. The kinetic energy of wind to mechanical energy of blade/turbine into electrical energy.
iii. The potential energy of water in dams to the kinetic energy of water flowing through penstock pipes into the mechanical energy of turbines into electrical energy.
iv. Nuclear energy to heat energy, heat energy of steam to mechanical (rotational kinetic) energy of turbine, mechanical to electrical energy

Q5- The conversion of part of energy into an unuseful form of energy is called _______.

Ans- Degradation of energy.