A transformer having efficiency of `90%` is working on `200 V` and `3 kW` power supply. If the current in the secondary coil is `6A`, the voltage across the secondary coil and current in the primary coil respectively are

Explanation

`i_(p) = p_(i n)/(V_(p)) = (3000)/(200) = 15A`
Efficiency `beta = ("output power")/("input power") = (p_(0))/(P_("in"))`
`(90)/(100) = P_(0)/(3000) implies P_(0) =2700W`
`P_(0) =V_(s) i_(s)`
`2700 =V_(s) xx 6 implies V_(s) =450V` .