Consider I1 and I2 are the currents flowing simultaneously in two nearby coils 1 & 2, respectively. If L1 = self inductance of coil 1, M12 = mutual inductance of coil 1 with respect to coil 2, then the value of induced emf in coil 1 will be :
- e1 = -L1 dI2dt - M12 dI1dt
- e1 = -L1 dI1dt + M12 dI2dt
- e1 = -L1 dI1dt - M12 dI1dt
- e1 = -L1 dI1dt - M12 dI2dt
Answer
(4) e1 = -L1 dI1dt - M12 dI2dt
Solution
Flux linked with coil 1 (own current + current of coil 2):
1 = L1 I1 + M12 I2
By Faraday's law, e1 = - d 1dt
e1 = -L1 dI1dt - M12 dI2dt
Answer: (4)