The coils having self inductor of 10 mH and 15 mH have an effective inductor of ___

The coils having self inductor of 10 mH and 15 mH have an effective inductor of 40 mH, when connected in series aiding.

What will be the equivalent inductor if we connect them in series opposing

A. 20 mH.
B. 5 mH.
C. 0 mH.
D. 10 mH.

Show Answer

Answer: D

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