The primary and secondary coils of a transmformer have `50` and `1500` turns respectively. If the magnetic flux `phi` linked with the primary coil is given by `phi=phi_(0)+4t`, where `phi` is in weber, `t` is time in second and `phi_(0)` is a constant, the output voltage across the secondary coil is

Options

A. 120 V.
B. 220 v
C. 30 V .
D. 90 V

Answer

A

Explanation

(a) Since `(V_(P))/(V_(s))= (N_(P))/(N_(S))`
`N_(P)= 50, N_(S)=1500`
From Faraday.s law `V_(P)=(dPhi)/(dt)=(d)/(dt)(Phi_(0)+4t)=4V`
`(V_(P))/(V_(s))=(50)/(1500)=(1)/(30)`
`V_(S)=30V_(P)=30xx4 = 120 V `