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Question
There are two coils A and B seperated by some distance. If a current of 2A flows through A, a magnetic flux of 10-2 Wb passes through B (no current through B). If no current passes through A and a current of 1A passes through B, what is the flux through A?
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Solution
Let IA current is passing through coil A having mutual inductance MAB with respect to coil B
NA = number of turns in coil A
NB = number of turns in coil B
`phi_A` = flux linked with coil A due to coil B
`phi_B` = flux linked with coil B due to coil A
MBA = Mutual inductance of coil B with respect to coil A
Then, Total flux through B = M2 Φ2 = MBAI1
10–2 = MBA × 2
MBA = `10^-2/2` = 5 mH
Now total flux through A = MA ΦA = MBAI2 ......[∵ MBA = MBA]
= 5 mH × 1 Wb
= 5 m Wb
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