Question

In a thermal power station, coal is used for the generation of electricity. How energy changes from one form to another before it is transformed into electrical energy?

(a) Heat energy->Mechanical energy->Electrical energy

(b) Heat energy->Electrical energy->Mechanical energy

(c) Mechanical energy->Heat energy->Electrical energy

(d) Electrical energy->Heat energy->Mechanical energy

The question was asked in examination.

Query is from Conservation of Energy in chapter Laws of Motion of Engineering Physics I

Answer 1

The correct answer is (a) Heat energy->Mechanical energy->Electrical energy

Easy explanation: The heat energy produced due to combustion of coal converts water into steam. The heat energy of steam is converted into mechanical energy when it turns blades of a turbine. The mechanical energy so obtained is converted into electrical energy by the generators.