# Basic Electrical Engineering Questions and Answers – Coupling Coefficient

This set of Basic Electrical Engineering Multiple Choice Questions & Answers (MCQs) focuses on “Coupling Coefficient”.

1. Mutual inductance between two coupled coils depend on?
b) Rate of change of flux linkage
c) Rate of change of current
d) Flux density

2. Which, among the following, is the correct formula to find the coupling coefficient?
a) k=M/sqrt(L1L2)
b) k=M/sqrt(L12)
c) k=M/sqrt(L22)
d) k=M/(L1L2)

3. What happens to the coupling coefficient when the flux linkage of coil 1 and coil 2 increases?
a) Increases
b) Decreases
c) Remains the same
d) Becomes zero
ortional to the mutual inductance hence as mutual inductance increases, the coupling coefficient increases.

4. What is the SI unit of coupling coefficient?
a) H
b) H-1
c) No unit
d) H2

5. Find the coupling coefficient if the Mutual inductance is 20H, the inductance of coil 1 is 2H and the inductance of coil 2 is 8H.
a) 5
b) 20
c) 2
d) 8

6. Find the value of x if the Mutual inductance is x H, the inductance of coil 1 is 2H and the inductance of coil 2 is 8H. The coupling coefficient is 5.
a) 10H
b) 20H
c) 16H
d) 15H

7. Find the value of x if the Mutual inductance is 20H, the inductance of coil 1 is xH and the inductance of coil 2 is 8H. The coupling coefficient is 5.
a) 2H
b) 4H
c) 6H
d) 8H

8. What is the coupling coefficient when all the flux of coil 1 links with coil 2?
a) 0
b) 100
c) 1
d) Insufficient information provided

9. What is the coupling coefficient when there is ideal coupling?
a) 0
b) 100
c) 1
d) Insufficient information provided

10. Can the coupling coefficient practically ever be equal to 1?
a) Yes
b) No
c) Depends on the current in coil 1
d) Depends on the current in coil 2

The coefficient of coupling between the two coils is the fraction of magnetic field produced by the current in one coil that links with the current in the other coil. When the current generated by one coil thoroughly links with the flux produced by the other coil and is called magnetic strongly tied, it is denoted by (k). Explanation: k=M/sqrt is the proper formula for the coupling coefficient (L1L2). The mutual inductance is M, and L1 and L2 are the inductance values of the first and second coils, respectively.