Question

Two inductors \( L_1 \) and \( L_2 \) are connected such that their fluxes are in opposite directions. The total inductance \( L \) will be:

• A. \( L = L_1 + L_2 + M \)
• B. \( L = L_1 + L_2 + 2M \)
• C. \( L = L_1 + L_2 - 2M \)
• D. \( L = L_1 + L_2 - M \)

Hint:

If inductors aid each other, use \( +2M \). If they oppose each other, use \( -2M \).

Answer 1

The Correct Option is C

When two inductors are connected in series but their fluxes oppose each other, the total inductance is: \[ L = L_1 + L_2 - 2M \] where \( M \) is the mutual inductance.