Question

A 10 kW transformer has 20 turns in primary and 100 turns in secondary circuit. A.C. voltage `E_(1) = 600 sin 314 t` is applied to the primary. Find max. value of flux and max. value of secondary voltage.

Answer 1

Here, `P_(0) = 10 kW = 10000 W, N_(P) = 20`,
`N_(s) = 100`
As `E_(1) = 600 sin 314 t :. E_(0) = 600 V`
`omega = 314 rad//s`
Flux linked with each turn of primary
`phi = BA cos omega t = phi_(0) cos omega t`
As `E_(1) = - N_(P) (d phi)/(dt) = - N_(P) (d)/(dt) (phi_(0) cos omega t)`
peak value of `E_(1) = E_(0) = omega N_(P) phi_(0) xx 1`
`:. phi_(0) = (E_(0))/(omega N_(P)) = (600)/(314 xx 20) = 0.0955 Wb`
As `(E_(s))/(E_(P)) = (N_(s))/(N_(P))`
`:. E_(s) = (N_(s))/(N_(P)) E_(P) = (100)/(20) xx 600 = 3000 V`