State the energy changes that occur in the following : (i) The unwind

1.	State the energy changes that occur in the following : (i) The unwinding of a watch spring. (ii) Burning coal while operating a steam engine. (iii) Lighting of a torch bulb. (iv) An electric generator (or dynamo).
Answer» (i) Potential energy to kinetic energy. (ii) Chemical energy of coal changes to heat energy of the steam. Heat energy changes into mechanical energy. (iii) Chemical energy into light and heat energy. (iv) Electrical energy change into mechanical energy.

State the energy changes that occur in the following : (i) The unwinding of a watch spring. (ii) Burning coal while operating a steam engine. (iii) Lighting of a torch bulb. (iv) An electric generator (or dynamo).

Answer»

(i) Potential energy to kinetic energy.

(ii) Chemical energy of coal changes to heat energy of the steam. Heat energy changes into mechanical energy.

(iii) Chemical energy into light and heat energy.

(iv) Electrical energy change into mechanical energy.