Question

In a 400 / 230 V single-phase 50 Hz transformer, the primary winding is connected to 400 V. Then the value of (EMF per turn in the primary winding) / (EMF per turn in the secondary winding) is:

Answer 1

Correct Answer - Option 3 : 1

RMS value of induced EMF in whole primary winding (E1) = 4.44 f N1 ϕm

RMS value of induced EMF in whole secondary winding (E2) = 4.44 f N2 ϕm

Where N1 = number of turns in the primary winding

N2 = number of turns in the secondary winding

ϕm = Maximum flux in the core (in Wb) 

f = frequency of the AC supply (in Hz)

\(\frac{{{E_1}}}{{{N_1}}} = \frac{{{E_2}}}{{{N_2}}} = 4.44f{\phi _m}\)

This is called the emf equation of transformer, which shows, (emf / number of turns) is the same for both primary and secondary winding.

Therefore, the value of (EMF per turn in the primary winding)/(EMF per turn in the secondary winding) is 1.