A coil of 100 turns is wound on a magnetic circuit of reluctance 1000 AT/mWb. The current of 1A flowing in the coil is reversed in 10 ms. The average EMF induced in the coil is ________ V.

Concept

The average EMF induced in the coil is given by:

\(E=-N{Δ ϕ \over Δ t}\)

The magnetic flux is given by:

\(ϕ = {NI\over R}\)

where, E = EMF

N = No. of turns

Δϕ = Change in flux

Δt = Change in time

I = Current

R = Reluctance

Calculation

Given, N = 100

I = 1 A

R = 1000 AT/Wb

When the current reverses, the flux changes from $+0.1$ Wb to $-0.1$ Wb.

The change in flux is given by:

Δϕ = ϕ_final - ϕ_initial

Δϕ = (−0.1) − (0.1) = −0.2 Wb

\(E=-(100)× {-0.2 \over 10× 10^{-3}}\)

E = 100 × 20 × 10^-3 V

E = 2 V