Networks Analysis and Synthesis - Engineering

Q1:

When two coupled coils of equal self inductance are cormected in series in one way the net inductance is 12 mH and when they are connected in the other way the net inductance is 4 mH. The maximum value of inductance when they are connected in parallel is

A 2 mH

B 3 mH

C 4 mH

D 6 mH

ANS:B - 3 mH

L1 = L2 = L = 4H. When in parallel effective inductance =