A transormer has an efficiency of `80%.` It is connectes to a power input of 5 kW at 200 V. It the secondary voltage is 250 V, the primary and secondary currents are respectively

Options

A. 25 A, 20A
B. 20 A, 16 A
C. 25 A, 16 A
D. 40 A, 25 A

Answer

C

Explanation

Efficiency `=("Output power")/("Input power")`
Input power `=5000W,`
Input voltage `=200 V`
`therefore` Primary current,` l_(p)=(5000)/(200)=25A`
Output power = 4000 W
Output voltage = 250 V
Secondary current, `l_(s)=(4000)/(250)=16A`