Question

The mutual inductance between two coils is

0.15 H

. If a current of

20 A

in the primary coil is cut off in

0.05 s

, find the emf induced in the secondary coil. If the secondary coil has

60

turns, then find the flux-change in it.

Accepted Answer

The emf induced in the secondary coil due to current in the primary coil is given by- $e = - M \frac{∆ I}{∆ t}$

Here, $e$ is the emf induced $M$ is the mutual inductance between the coils $60$ is the change in current $Δt$ is the change in time.

Given, mutual inductance between two coils is $0.15 H,$ initial current in primary coil is $20 A$ and the final current is $0 .$ Therefore, change in current will be $ΔI = 0 - 20 = - 20 A$ and $Δt = 0.05 s$

Substituting given values in the above equation, we get,

Emf induced is $e = - 0.15 \times \frac{- 20}{0.05} = 60 V$ $= 60 V$

Therefore, the emf induced in the secondary coil is $60 V .$

The change in flux in secondary coil is given by- $ϕ = MΔI$

Here, $ϕ$ is the change in flux

We substitute given values in the above equation to get, $ϕ = 0.05 \times - 20 \Rightarrow ϕ = - 3 Wb$

Therefore, the change in flux in the secondary coil is $- 3 Wb$ . The negative flux indicates that the change in flux opposes the change in current in the secondary coil.

Therefore, the emf induced in the secondary coil due to change in current in the primary coil is $20 A$ and the magnitude of flux change in the primary coil is $3 Wb .$

The mutual inductance between two coils is $0.15 H$ . If a current of $20 A$ in the primary coil is cut off in $0.05 s$ , find the emf induced in the secondary coil. If the secondary coil has $60$ turns, then find the flux-change in it.

Important Questions on Electromagnetic Induction

Learn and Prepare for any exam you want !

The mutual inductance between two coils is 0.15 H. If a current of 20 A in the primary coil is cut off in 0.05 s, find the emf induced in the secondary coil. If the secondary coil has 60 turns, then find the flux-change in it.

Important Questions on Electromagnetic Induction

Learn and Prepare for any exam you want !

The mutual inductance between two coils is $0.15 H$ . If a current of $20 A$ in the primary coil is cut off in $0.05 s$ , find the emf induced in the secondary coil. If the secondary coil has $60$ turns, then find the flux-change in it.