Question

The total inductance of two inductances \(L_1\) and \(L_2\) with series opposing connection and mutual inductance \(M\) is:

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

Hint:

Use \(L_{\text{total}} = L_1 + L_2 \pm 2M\) depending on aiding or opposing configuration.

Answer 1

The Correct Option is D

For inductors in series with mutual coupling:
- If aiding: \(L_{\text{total}} = L_1 + L_2 + 2M\)
- If opposing: \(L_{\text{total}} = L_1 + L_2 - 2M\)
Since the connection is series opposing, use the second formula.