The primary and secondary coil of a transformer have 50 and 1500 turns respectively. If the magnetic flux Φ linked with the primary coil is given Φ = Φ_o +4t, where Φ is in weber, t is time is second and Φ_o is a constant the output voltage across the secondary coil is:

90 V

120 V

220 V

30 V

Answer

120 V

The magentic flux linked with the primary coil is given by
Φ = Φ_o +4t
So, voltage across primary
V_p = dΦ/dt = d(Φ+dt) /dt
= 4 volt (Φ = constant)
Also, we have
N_p = 50 and N_s = 1500
From relation ,
V_s/V_p = N_s/N_p
V_s = 4 x (1500/50)
= 120 V