Question

a planar loop of rectangular shape is moved within the region of a uniform magnetic field acting perpendicular to its plane. what is the direction and magnitude of the current induced in it?

Answer 1

The flux through the conducting loop increases as it moves in the plane perpendicular to magnetic field B.  Let B be pointing in +ve z direction, ie., direction perpendicular to the plane of this page and coming out of this page. So the loop is in x-y plane, ie., plane of this page.

The current i induced in it will be in the direction opposite to the given magnetic field B. Then the current will be in the clockwise direction in the loop.  This is as per Lenz's law.

Magnitude of current = - B L v / (R+r),
        L = width of rectangular loop perpendicular to velocity.
        v = speed of the loop
        R = resistance of loop,  and  internal resistance r

Answer 2

Answer:

The flux will remain constant hence no current will flow through the loop.

Explanation:

When the loop is moved perpendicularly within the region of magnetic field, no change in flux occurs.

We know that d(Ф)/dt = ε

d(Ф)/dt = 0 for the above question ⇒ ε = 0 ⇒ I(induced)= 0