The nichrome heating element in an electric drier operates on 240 V and generates heat at the rate of 2.0 kW. The heating element shorts out and, in repairing it, the repairman shortens the
Nichrome wire by 10%. (Assume the temperature is unchanged. In reality, the resistivity of the
Wire will depend on its temperature.) What effect will the repair have on the power dissipated in
The heating element?
A) The power is still 2.0 kW.
B) The power decreases to 1.8 kW.
C) The power increases to 2.2 kW.
D) None of the given answers is correct.

Question

Quizplus · Accepted Answer

When the length of the wire is shortened by 10%, its resistance decreases by 10% (since resistance is directly proportional to length). With a constant voltage, the power dissipated (P = V^2/R) will increase because the resistance has decreased.

The Nichrome Heating Element in an Electric Drier Operates on 240