Question

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

Answer 1

Power loss in the transmission line in the form of heat
`P = I^(2) R= (P/V)^(2) R = ((20,000)/(220))^(2) xx 0.4`
`= 3306 W = 3.31 kW`
Efficiency of transmission line
`eta = ("power delivered by line")/("power supplied to line")`
`= ("power delivered")/("power delivered + power loss")`
`= 20/(20+3.31) = 0.858 = 85.8%`