| Directions : (46-50) |
| Heat Produced bt Electric current |
| Whenever an electric current is passed through a conductor, it becomes hot after some time. The phenomenon of the production of heat in a resistor by the flow of an electric current through it is called heating effect of current or Joule heating. Thus, the electrical energy supplied by the source of emf is converted into heat. In purely resistive circuit, the energy expended by the source entirely appears as heat. But if the circuit has an active element like a motor, then a part of the energy supplied by the source goes to do useful work and the rest appears as heat. Joule's law of heating form the basis of various electrical appliances such as electric bulb, electric furnace, electric press etc. |
 |
A) Heat produced in a conductor is independent of the current flowing.
B) Heat produced in a conductor varies inversely as the current flowing.
C) Heat produced in a conductor varies directly as the square of the current flowing.
D) Heat produced in a conductor varies inversely as the square of the current flowing.
Correct Answer: C
Solution :
According to Joule's law of heating, heat produced in a conductor \[H={{I}^{2}}Rt\] where, I = current flowing through the conductor R = resistance of the conductor t = Time for which current flows through the conductor. \[\therefore \,\,\,H\propto {{I}^{2}}\]
You need to login to perform this action.
You will be redirected in
3 sec
