An 5.00-Ω resistor is dissipating 80 watts.What are the current through it and the difference of potential across it?

A) 16 A,20 V
B) 20 A,4 V
C) 4 A,20 V
D) 4 A,16 V
E) 16 A,80 V

Question

An 5.00-Ω resistor is dissipating 80 watts.What are the current through it and the difference of potential across it?
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A) 16 A,20 V
B) 20 A,4 V
C) 4 A,20 V
D) 4 A,16 V
E) 16 A,80 V

Quizplus · Accepted Answer

Using the formula for power, P = I^2*R, we can solve for the current:

80 W = I^2 * 5 Ω 
I^2 = 16 A^2 
I = 4 A

Next, we can use Ohm's law to solve for the voltage:

V = I * R 
V = 4 A * 5 Ω 
V = 20 V

Therefore, the correct answer is C.

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