Test: Electromagnetic Induction - 1 - CUET Humanities MCQ

The mutual inductance between the two coils in orientation (A) is the maximum since the flux linkage in (A) is the maximum as shown in fig.

Electromagnetic induction is a current produced because of voltage production (electromotive force) due to a changing magnetic field. This either happens when a conductor is placed in a moving magnetic field (when using AC power source) or when a conductor is constantly moving in a stationary magnetic field.

When the key is pressed, a current starts building up in the coil and the magnetic flux through the neighbouring coil increases.
By Lenz's law, the induced current in this coil must oppose this increase in flux.
Hence the induced current must flow in the anticlockwise direction, i.e. along ABC.

The phenomenon of induction of an emf in a circuit, due to change in magnetic flux with time linked with it, is called electromagnetic induction. We can change the magnetic flux by changing the magnetic field.

Magnetic flux  = BA ...(i)
and also F = ilB or B =  ...(ii)
Now, from Eqs. (i) and (ii)
 = 
Dimensions of = 
= [ML² T^-2 I^-1]

A wireloop of radius R confined in a plane is rotated in its plane with some angular velocity. A uniform magnetic field exists in the region. The emf induced is zero as no area is swept by thin loop or we can say that there is no change in the magnetic flux linked with it.

Work done = Change in potential energy
= Charge x Change in potential
= QV
(As the induced electric field is non-conservative in nature)

Induced currents always produce expanding magnetic fields around their conductors in a direction that opposes the original magnetic field. This law is called Lenz's law. Lenz's law states that the direction of an induced e.m.f. will be such that if it were to cause a current to flow in a conductor in an external circuit, then that current would generate a field that would oppose the change that created it.

Induced emf e = -L (dl/dt).Therefore,

Hence the correct choice is (1).