Q17 of 269 Page 148

What are the two ways in which cow-dung can be used as a fuel? Which of them is better and why?

Two ways in which cow-dung can be used as a fuel are:

a) In the form of cow-dung cakes, which can be used directly as a fuel.

b) By preparing biogas from cow-dung.

What is biomass? Give three examples of biomass.

Name the biomass which is still widely used as a source of heat energy in many households of country.

How is charcoal prepared? Explain why, charcoal is a better fuel than wood.

Compare and contrast biomass and hydroelectricity as sources of energy.