An electric generator with a power output of 3.0KW at a voltage of 1.5KV distributes power along cables of resistance 20.0Ω. The power loss in the cables is?

A. 80.0W
B. 40.0W
C. 10.0W
D. 0.1W

Correct Answer:

Option A = 80.0W

Explanation

Power input = 3KW = 3000W
Voltage = 1.5KV = 1500V
Current (I) = P/V = 3000/1500 = 2Amps.
∴ Power loss in the cables = I²R
= 2 x 2 x 20
= 80W