Question 1

What is a good source of energy? State two main characteristics.

Accepted Answer

A good source of energy is one which would do a large amount of work per unit volume or mass, be easily accessible, easy to store and transport, and economical. Two main characteristics are: firstly, it should produce a large amount of useful energy per unit mass or volume, and secondly, it should b

Question 2

Why is solar cooker painted black from inside?

Accepted Answer

A solar cooker is painted black from the inside because black surfaces are known to be excellent absorbers of heat and thermal radiation compared to white or shining surfaces. By absorbing maximum solar radiation falling on it, the black interior helps in raising the temperature efficiently inside t

Question 3

State two limitations of harnessing wind energy.

Accepted Answer

Harnessing wind energy has several practical limitations, among which two major ones are: firstly, wind energy farms can be established only at specific coastal or open locations where the wind blows consistently at a high speed throughout a major part of the year. Secondly, setting up windmills req

Question 4

What are the qualities of an ideal source of energy? Explain any two.

Accepted Answer

An ideal source of energy is one which would do a large amount of work per unit volume or mass, be easily accessible, be easy to store and transport, and perhaps most importantly, be economical. First, it should have a high calorific value, meaning it releases a large quantity of heat per unit mass

Question 5

Differentiate between renewable and non-renewable sources of energy with suitable examples.

Accepted Answer

Renewable sources of energy are those that are inexhaustible and can be replenished continuously by nature over a relatively short period of time. Examples include solar energy, wind energy, hydroelectricity, and biomass. They are generally clean and cause minimal pollution. On the other hand, non-r

Sources of Energy