A step-down transfomer reduces the voltage of a transmission line from 2200 V to 220 V. the power delivered by it is 880 W and its efficiency is 88%. The input current is

Options

A. 4.65 mA
B. 0.045 A
C. 0.45 A
D. 4.65 A

Answer

C

Explanation

Efficiency of transformer, ltbr. `eta=("Output power")/("Input power")`
`implies (88)/(100)=(800)/(P_(i)) implies P_(i)=1000W`
Input current, `l_(p)=(P_(i))/(V_(i))=(1000)/(2200)=0.45A`