question_answer 71)

  Draw an appropriate schematic diagram showing common domestic circuits and discuss the importance of fuse. Why is it that a burnt out fuse should be replaced by another fuse of identical rating?

Answer:

                  The schematic diagram of common domestic circuit is shown below Fuse is a safety device having short length of thin wire made of tin (25%) and lead (75%)alloy having low melting point around 200°C. It is an important component of all domestic circuits. A fuse in a circuit prevents damage to the appliances and the circuit due to overloading and short-circuiting. The use of an electric fuse prevents the electric circuit and the appliance from a possible damage by stopping the flow of unduly high electric current. The fuse is placed in series with the device. A fuse wire works because of its lower melting point which is possible. If a fuse with larger rating is used with an appliance, the fuse wire shall not melt and hence would fail to serve the required purpose. Due to this, a fuse with defined rating should not be replaced by one with a larger rating.