Current Electricity Charging Discharging Of Capacitors Question 736
Question: 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\Omega $ . The power loss in the wires is:
Options:
A) 19.2 W
B) 19.2 kW
C) 19.2 J
D) 12.2 kW
Show Answer
Answer:
Correct Answer: B
Solution:
[b] Total resistance $ R=( 0.5\Omega /km )\times ( 150km )=75\Omega $ Total voltage drop $ =( 8V/km )\times ( 150km )=1200V $ Power loss $ ~=\frac{{{( \Delta V )}^{2}}}{R}=\frac{{{( 1200 )}^{2}}}{75}W $
$ =19200W=19.2kW $
BETA
