Soil erosion can be prevented by

(a)

deforestation

(b)

afforestation

(c)

over growing

(d)

removal of vegetation

Soil erosion is more where there is

(a)

no rainfall

(b)

low rainfall

(c)

rainfall is high

(d)

none of these

Common energy source in village is

(a)

electricity

(b)

coal

(c)

biogas

(d)

wood and animal dung

A cheap, conventional, commercial and inexhaustible source of energy is

(a)

hydropower

(b)

solar energy

(c)

wind energy

(d)

thermal energy

Which of the following statement is wrong with respect to wind energy

(a)

wind energy is a renewable energy

(b)

the blades of wind mill are operated with the help of electric motor

(c)

production of wind energy is pollution free

(d)

usage of wind energy can reduce the consumption of fossil fuels.