A sinusoidal flux 0.02 Wb links with 55 turns of a transformer secondary. What is the rms value of the induced emf in the secondary, if the supply frequency is 50 Hz ?

Concept: 

In a transformer, an alternating current is applied to the primary winding, a current in the primary winding (magnetizing current) produces alternating flux in the core of the transformer. This alternating flux gets linked with the secondary winding, by mutual induction, so an emf gets induced in the secondary winding. This induced emf is given by the EMF equation of the transformer.

The rms value of Emf equation of the transformer is given by,

E = 4.44 N ϕm f

The average value of Emf equation of the transformer is given by,

E = 4 N ϕm f

Where N is the number of turns

f is the supply frequency

ϕm is the flux

Calculation:

Given, 

flux ϕ = 0.02 Wb

N₂ = 55

frequency f = 50 Hz

⇒ E_rms = 4.44 × 0.02 × 55 × 50 = 244.2 V