i] Define electric potential difference. How is ammeter connected in an electric circuit ?
ii] Explain the application of heating effect of electric current E in an electric bulb and the fuse used in an electric circuit.

Explanation

i] Potential difference is defined as the difference in electrical potential energy between two points. An ammeter is connected in series in an electric circuit.
ii] When electric current is passed through a bulb, its filament gets heated to a very high temperature. The electrons in the filament get excited and emit light. Thus, heating effect of electric current is used to produce light energy in an electric bulb.
A fuse is a safety device used in electric circuits and is made of a wire of metal or alloy with low melting point and high resistance. When a high current flows in a fuse, it heats the wire in the fuse and melts it thereby breaking the circuit. Thus, fuse protects electrical appliances from getting damaged.