A coil with a self-inductance of 5 H is coupled with another coil having a self-inductance of 20 H in such a way that the mutual inductance is 8 H. Find the coefficient of coupling.

Question

Question

This question was previously asked in

MPPGCL JE Electrical 28 April 2023 Shift 2 Official Paper

Answer 1

Coefficient of coupling

The coupling coefficient can be defined as a magnetic flux produced between two different coils while managing the flux successfully.

\(k={M\over \sqrt{L_1L_2}}\)

where, k = Coefficient of coupling

M = Mutual inductance

L1 and L2 = Self-inductance of two coils

Calculation

Given, L1 5H & L2 = 20 H

M = 8 H

\(k={8\over \sqrt{5\times 20}}\)

k = 0.8