Question : 120 kW of power is sent from a power plant to a town 10 km away. The resistance of the transmission lines is 0.40 Ω.
a)Calculate power loss if the transmission lines are at 24 kV.
b) Calculate the power loss if the transmission lines are at 240 V.
Doubt by Aadhya
Solution :
P = 120 kW
= 120×103 W
Resistance of Transmission Lines,
R = 0.40 Ω
a) V1 = 24 kV
= 24×103 V
Current in the Transmission Lines,
I1 = P/V1
=(120×103)/(24×103)
= 5 A
Power loss,
P1 = I12R
= (5)2×0.40
= 25×0.40
= 10 W
b) V2 = 240 V
Current in the Transmission Lines,
I2 = P/V2
=(120×103)/(240)
= 500 A
Power loss,
P2 = I22R
= (500)2×0.40
= 250000×0.40
= 100000 W
= 100 kW
