What type of energy is possessed by flowing water?

The pollution of air caused by burning petroleum fuels (like petrol and diesel) in vehicles can be controlled by fitting a device X in the exhaust system of vehicles.

(a) Name the device X

(b) How does this device help in controlling air pollution ?

A hydro-power plant converts one from of energy into another. Name the two forms of energy.

Flowing water can rotate a turbine. Which type of energy is used up by the turbine?

Name the original source of wind energy.