Question

Induced current is produced in a coil, only when its ends are____________.
$\left( {\text{A}} \right)$Not closed
$\left( {\text{B}} \right)$ Closed
$\left( {\text{C}} \right)$ Both A and B
$\left( {\text{D}} \right)$ None of the above

Answer 1

Induced current: It is defined as the electric current that results when a second conductor is placed in an area where there is already an electric current.
The induced current depends on the area of the cross-section of the coil and it also depends on the change in the magnetic field.
Induced emf in a coil: It is defined as the negative rate of change of the magnetic flux times the number of turns in the coil.

Complete step by step answer:
Induced current and induced emf in the coil is alternating.
Self-induction is defined as the phenomenon in which an induced emf is produced by changing the electric current in a coil.
Eddy current is defined as when a conductor is moved in a magnetic field, induced currents are generated in the whole volume of the conductor.
When the coil is not connected to the battery (open), there is no change in the magnetic field in the circuit and induced current will not be generated in the coil.
When the coil is connected to the battery (closed), there is a change in the magnetic field through the coil which results in the production of emf in the coil and the induced emf turns into the induced current in the coil.

Hence, the correct option is $\left( {\text{B}} \right)$.

Note:
The difference between current and induced current is that current is just a normal current that flows in the circuit whereas the induced current is generated only when the magnetic field is produced in the coil.
There are few ways to induce a current in the coil
$\left( 1 \right)$ If the coil is moved rapidly between the two poles of a horseshoe magnet.
$\left( 2 \right)$ If a magnet is moved relative to the coil.