Numerical problems based on Faraday’s Law

In this post, let’s solve numerical problems based on Faraday’s Law.

1 )

A coil of wire with 50 turns has a uniform magnetic field of 0.4 T passing through the coil perpendicular to its plane. The coil encloses an area of 0.03 m². If the flux through the coil is reduced to zero by removing it from the field in a time of 0.25 seconds, what is the induced voltage in the coil?

Solution:

N = 50 turns
B = 0.4 T
A = 0.03 m²
t=0.25s

The initial flux through the coil is ф = NBA =50 x 0.4 x 0.03 Tm² =0.6 Tm²
The induced voltage is equal to the rate of change of flux: Ɛ = Δф/t = (0.6-0)/0.25 = 2.4 V