Electricity

a) Derive the expression for the heat produced due to a current I flowing for a time interval t through a resistor R having a potential difference V across its ends. With which name is this relation known? b) How much heat will an instrument of 12W produce in one minute if it is connected to a battery of 12V? c) The current passing through a room heater has been halved. What will happen to the heat produced by it? d) What is meant by the heating effect of current? Give two applications of the heating effect of current. e) Name the material which is used for making the filaments of an electric bulb.

Answer a) The amount of work done when an electric charge Q moves against a potential difference V is: W = Q V = W = Q V = W = Q V = W = Q V (1) We all know that current I = Q/T. IT = Q (2)...

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