In a single-phase transformer, the ratio of transformation is 2 and the secondary resistance is 0.24 Ω. Find the resistance of secondary in terms of primary.

Question

Question

This question was previously asked in

HPCL Engineer Electrical 01 Nov 2022 Official Paper

Answer 1

The correct answer is option 4):(0.06 Ω )

Concept:

Turns Ratio = \(N_1\over N_2\)

Transformation Ratio (K)= \(N_2\over N_1\)

Where

N₁ = number of turns in the primary winding of the transformer

N₂= number of turns in the secondary winding of the transformer The resistance offered by secondary winding in the terms of primary is

R₂' = \(R_2\over (K)^2\)

Where

R₂ = Resistance connected across the secondary winding.

Calculation:

K = 2

R₂ = 0.24 Ω

R2' = \(R_2\over (K)^2\)

= \(0.24 \over 4\)

= 0.06 Ω