Question

A circular coil is entering a magnetic field as shown. What is the direction of induced current?

1) Clockwise.
2) Anti Clockwise.
3) No induced current.
4) Both Anti clockwise and clockwise.

Answer 1

Hint:- Here the induced current in the coil is in the direction that opposes the source it is produced from. This phenomenon is known as Lenz’s law. Here apply the same concept and choose the suitable option.

Complete step-by-step solution:-
Lenz law states that an induced current flows in a direction such that the current opposes the change that induced it. Here the coil is just entering in the magnetic field B so the flux is changing also according to the Lenz law the direction of the current induced would be in the opposite direction. Here the magnetic flux is defined as the number of magnetic field lines passing through it. The SI unit of magnetic flux is weber. According to Lenz law the current induced in the coil would be in anticlockwise direction.
Final Answer: Option “2” is correct. The direction of induced current would be anticlockwise.

Additional Information: Lenz law was named after a famous physicist Emil Lenz who formulated this law in the year 1834. It is a law that is used for specifying the direction of an induced current. The Lenz law states nothing about the magnitude of the induced current it just gives the direction of the induced current.

Note:- Here the flux is changing because the coil is just entering the magnetic field. If the coil has already entered the magnetic field and then it would be moved inside the magnetic field then there would be no flux change and hence there would be no induced current.