Science
Anannya responded to the question: Why do electrical appliances with metallic bodies are connected to the mains through a three pin plug, whereas an electric bulb can be connected with a two pin plug?
She wrote: Three pin connections reduce heating of connecting wires.
(i) Is her answer correct or incorrect? Justify.
(ii) What is the function of a fuse in a domestic circuit?
Answer
(i) Anannya's answer is wrong. Electrical appliances with metallic bodies need an earth wire which provides a low resistance conducting path to the flow of current in the case when there is an accidental leakage of current through the conducting body of the appliances.
(ii) An electric fuse safeguards the circuit and appliances connected in the circuit from being damaged if the current in the circuit exceeds the specified value due to voltage fluctuations or short circuiting. An important component of an electrical fuse is a metal wire or strip that melts when excess current flows through it.
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