List any four sources of energy which are selected for use for a given activity.
1. Energy to run a cycle
2. Energy to run a car
3. Energy to cook food
4. Energy to work on
Four sources of energy used in the activity is:
1. Energy of muscles
2. Chemical energy of petrol or diesel
3. Chemical energy of gas or kerosene
4. Electrical energy obtained from potential energy. Electrical appliances of water, chemical energy of fuels etc.
In general a good source of energy would be one,
(i) which would do a large amount of work per unit mass or volume
(ii) which would be easily accessible.
(iii) which can be easily stored and transported.
(iv) which is also reasonably economical.
Which of the following is not an example of a bio-mass energy source?