Question

Calculate the value of equivalent inductance for series aiding of two coils whose self inductances are 5 H, 2 H, and mutual inductance value is 4 H.

(a) 15 H

(b) 12 H

(c) 13 H

(d) 11 H

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Asked question is from Regenerative Braking of DC Shunt Motors topic in section Braking of DC Motors & Induction Motors of Electric Drives

Answer 1

Right option is (a) 15 H

The explanation is: The equivalent inductance for series aiding of two coils is Leq=L1+L2+2M=5+2+8=15 H. The value of equivalent inductance increases due to mutually induced e.m.f in case of the magnetically coupled circuit.