Q. Two cities are 150 km apart. Electric power is sent from one city to another city through copper wires. The fall of potential per km is 8 volt and the average resistance per km is 0.5 Ω. The power loss in the wire is :
A) 19.2 W
B) 19.2 kW
C) 19.2 J
D) 12.2 kW
Explanation
[Solution] V = 8 × 150 = 1200 V, R = 0.5 × 150 = 75 Ω; P = $\frac{V^2}{R} = \frac{1200^2}{75} = 19.2$ kW. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.