The nichrome heating element in an electric drier operates on 240 V and generates thermal energy 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 increases to 2.2 kW.
C)The power decreases to 1.8 kW.
D)None of the given answers is correct.

Question

Quizplus · Accepted Answer

Shortening the wire by 10% reduces its resistance since resistance is directly proportional to length (R = ρL/A, where ρ is resistivity, L is length, and A is cross-sectional area). With lower resistance, the power dissipated, given by P = V^2/R, increases because the voltage remains constant at 240 V.

The Nichrome Heating Element in an Electric Drier Operates on 240