Figure shows a conducting square loop placed parallel to the pole-faces of a ring magnet. The pole-faces have an area of 1 cm² each and the field between the poles is 0.10 T. The wires making the loop are all outside the magnetic field. If the magnet is removed in 1.0 s, what is the average emf induced in the loop?

Question

Philoid · Accepted Answer

Given:

Area of pole faces A=

Magnetic field intensity =0.1T

Time taken to remove the magnet completely

Initial magnetic flux through the loop is given by formula

Since magnetic field through the square loop is perpendicular to the loop above eqn. reduces to

…(i)

When the magnet is removed after 1s the magnetic flux passing through the square loop becomes zero

…(ii)

Average induced emf in time interval Δt is given by

…(iii)

Where

are flux across the cross section at time intervals respectively.

Using eqns.(i), (ii) and (iii) we get,

Putting the values of B, A and Δt in the above eqn.

Therefore average emf induced in the square loop is