An 8.00-W resistor is dissipating 100 watts.What are the current through it and the difference of potential across it?
A)12.5 A,28.3 V
B)3.54 A,12.5 V
C)3.54 A,28.3 V
D)28.3 A,3.54 V

Question

Quizplus · Accepted Answer

Using the formula P=I^2*R and P=V^2/R, we can find the current and voltage.

P=I^2*R 
100 = I^2 * 8 
I = sqrt(100/8) = 3.54 A

P=V^2/R 
100 = V^2/8 
V = sqrt(100*8) = 28.3 V

Therefore, the current through the resistor is 3.54 A and the difference of potential across it is 28.3 V. The answer is C.

An 800-W Resistor Is Dissipating 100 Watts