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October 22, 2017

Power Consumption of Electric Heater (KVPY '10)

Let's discuss a problem and know how to find the power consumption of electric heater. Try the problem and read the solution here.

The Problem:

An electric heater coonsists of a nichrome coil and under (220V)
consuming (1KW) power. Part of its coil burned out and it was reconnected after cutting off the burnt portion. The power it will consume now is:
(A) more than (1KW)
(B) less than(1KW), but not zero
(C) (1KW)
(D) 0kW


Part of coil is burnt. Then it was cut off. Hence resistance decreases. Hence there will be more current flow.
ELectric power $$ P=I^2R$$
Hence, power consumption will increase.

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