91Ó°ÊÓ

i) The conducting bar is slid with the same speed v in two circuits.

ii) The circuits are placed in a uniform magnetic field.

iii) The parallel lengths of the wire are separated by 2L in circuit 1 and by L in circuit 2.

iv) The current induced in circuit 1 is counterclockwise.

When the magnetic flux through an area bounded by conducting loop changes, it induces the current in the loop. The induced current produces its own magnetic field and emf. The direction of the induced current and field is decided using Lenz’s law. The magnitude of the induced emf depends upon the area and the magnitude of flux.

Formulae are as follow:

$\mathrm{Î\mu }=-N\frac{dâˆ\dots }{dt}$

Where,

E = induced emf,

$dâˆ\dots$= change in magnetic flux,

N = number of turns in coil,

dt = change in time.

The current induced in a circuit is such that it opposes the changing magnetic flux. In circuit 1, the induced current is counterclockwise. Hence, the magnetic field must be on the page.

Hence, the direction of the magnetic field is on the page.

The magnetic field is perpendicular to the plane of circuit 2. Also, the magnetic flux increases as the bar slides. Hence, the induced current will be counterclockwise.

Hence, the direction of the current induced in circuit 2 is counterclockwise.

The induced emf is directly proportional to the separation as below,

V = Blv ,

$V∞l$,

Hence,the emf induced in circuit 1 is larger than that in circuit 2.

The changing magnetic flux induces the current and the emf in the conductor. The direction of the induced current is decided using Lenz’s law. The magnitude of the emf induced is decided by Faraday’s law.