An inductor of 0.1 H is connected in series with an inductor of 0.4 H. If the coefficient of coupling is 0.6, then find the mutual inductance between them.

Question

Question

This question was previously asked in

HPCL Engineer Electrical 01 Nov 2022 Official Paper

Answer 1

The correct answer is option 1):(0.12 H)

Concept:

When two coils are connected in series additive polarity, the equivalent inductance is

L_eq1 = L₁ + L₂+ 2M

F1 U.B Madhu 07.01.20 D21

M = K \(\sqrt{L_1 \times L_2}\)

Where L₁ and L₂ are self-inductances of the coils M is the mutual inductance

Calculation:

Given that, L1= 0.1 H,

L₂ = 0.4 H

K = 0.6

For additive polarity,

M = K \(\sqrt{L_1 \times L_2}\)

M = 0.6 \( \sqrt{0.1 \times 0.4} \)

= 0.12 H