Two coupled coils, each of self-inductance L = 0.2 H, have a coupling co-efficient k = 0.9. The mutual inductance M is:

Two coupled coils, each of self-inductance L = 0.2 H, have a coupling

1.	Two coupled coils, each of self-inductance L = 0.2 H, have a coupling co-efficient k = 0.9. The mutual inductance M is:
A.	0.18 H
B.	0.23 H
C.	0.36 H
D.	0.43 H
Answer» B. 0.23 H