# Electronics - Transformers - Discussion

### Discussion :: Transformers - General Questions (Q.No.3)

3.

The coefficient of coupling between two coils is 0.45. The first coil has an inductance of 75 mH and the second coil has an inductance of 105 mH. What is the mutual inductance between the coils?

 [A]. 3.54 mH [B]. 7.88 mH [C]. 39.9 mH [D]. 189.3 mH

Explanation:

No answer description available for this question.

 Vinay said: (Oct 30, 2010) m=1(L1+L2)^1/2

 Suri said: (Jan 28, 2011) m=k*(L1*L2)^1/2

 Ambuj said: (Apr 6, 2011) Suri what is the value of k.

 Asha said: (Apr 20, 2011) K IS THE COEFFICIENT BETWEEN TWO COILS

 Mani said: (Sep 9, 2011) M=k*(L1*L2)^(1/2) where K=co-efficient of coupling that is given as K=.45

 Xyz said: (Feb 15, 2012) Coefficient of coupling (K) = 0.45 L1 = 75 mH L2 = 105 mH Mutual inductance M = k/(Root of L1 * L2) M = 0.45 / Root of L1 * L2 M= 39.9 mH

 Tito said: (Aug 1, 2013) M = K*square root(L1 X L2).

 Sunil Sharma said: (Jan 10, 2014) Let coefficient of coupling b/w two coils is = K. So, K = 0.45. First coil inductance(L1) = 75mh. Second " " " (L2) = 105mh. Mutual inductance(M) = k/square root of (L1*L2). M = 0.45*square root(75*105). M = 39.9.

 Bala Ram said: (Jul 14, 2016) Mutual inductance formula is M = K * root(L1*L2).

 Mega.K said: (Jun 21, 2017) Mutual inductance(M)=k*√(L1*L2). Formula : K=M/√(L1*L2) for finding coefficient coupling, So the answer is 0.45*88.74 = 39.9mH , M=K *√(L1*L2) for finding mutual inductance.

 Sukruth said: (Aug 3, 2018) M = K * √(L1*L2).