A line having a total resistance of `0.2Omega` delivers 10kW at 220V to a small factory. Calculate the efficiency of the transmission.

Options

A. 0.65
B. 0.75
C. 0.85
D. 0.95

Answer

D

Explanation

Let x watt be the power loss in transmission line in the form of heat.
`therefore x=((P)/(V))^(2)R=((10xx1000)/(200))^(2)xx0.2=500W=0.5kW`
Efficiency of transmission
`=("power delivered by line")/("power supplied to line")=(10kW)/(10kW+xkW)`
`=(10)/(10+0.5)=(10)/(10.5)=0.95=95%`