The maximum flux density in the core of a 300/3000 V, 50 Hz single phase transformer. If the EMF per turn is 10 V, determine primary and secondary turns, respectively.

Question

Question

This question was previously asked in

DFCCIL Executive Electrical 30 Sept 2021 Official Paper

Answer 1

Concept :

Transformation Ratio :

Transformation ratio is defined as the ratio of secondary voltage to the primary voltage.
It can also be defined as the ratio of the number of turns in the secondary winding to the number of turns in the primary winding.
It can also be related to the current flowing in the primary winding to the current flow in the secondary winding.
It is represented by the letter ‘K’

K = (E2 / E1) = (N2 / N1) = (I1 / I2)

Calculations :

Given ELV = 300 V, EHV = 3000

Emf per turn = 10 V

ELV = NLV × emf per turn

∴ NLV = ELV / emf per turn

Similarly NHV = EHV / emf per turn

NLV = 300 / 10 = 30

NHV = 3000 / 10 = 300