What is the source of energy?
A source of energy is one which provides an adequate amount of energy in a convenient form over a long period.
What are the needs for energy?
Making food, transportation, lighting, running machine etc.
What are the qualities of a suitable fuel?
High-calorie value, easily accessible, easy to transport, less environmental pill, etc.
What are the sources of energy?
Conventional and non-conventional
What are the fossil fuels?
Coal, petroleum etc.