(a) What is an electric motor ? Write the principle on which its working is based .
(b) What is short circuit ? Give its possible cause.

Explanation

(a) Electric motor is a device which transforms the electric energy into kinetic energy for doing work.
The working of electric motor is based on 'Fleming's left hand rule'. This rule states that , "If we hold the forefinger, middle finger and thumb of our left hand, mutually perpendicular to each other, and if forefinger gives the direction of current, then the thumb gives the the direction of motion of the conductor due to force acting on it.
(b) short circtui: When live wire comes in contact with the neutral wire in between the circtuit, then a lot of current flows abruptly through the circuit. such a phenomenon is known as short circuit. When many electric appliances are connected in one circuit (through the same switch), then short circuit can occur.