Question

Looking from one side towards the face of a coil. The current in it flows in clockwise direction. On looking from the opposite side towards the second face of the coil, the current flows in –
A) Anti-clockwise direction and this face represents the south pole.
B) Clockwise direction and this face represents the south pole.
C) Anti-clockwise direction and this face represents the north pole.
D) Clockwise direction and this face represents the south pole.

Answer 1

Hint: We know that the current in an induced coil follows a definite direction and produces magnetic dipoles according to its movement. We have simple techniques to identify this. The north pole and south pole can be recognised by knowing the direction of current induced.

Complete answer:
Any coil in a magnetic field subject to change in magnetic field with time induces an electromotive force which results in a current flow in the coil. This is the Faraday’s law of electromagnetic induction.
We also know that there is always a resistance offered by the coil against the change which is the sole reason for induced emf. Lenz's law gives this idea to the induction.
Now let us consider the coil as per the question. A coil is said to have current in it due to the induction which is in the clockwise direction as seen from side A.

           

The image shows the direction of current as seen from both the ends.
We can use the right-hand thumb rule to determine the pole of the magnetic field at A given the direction of the current. Let the curly fingers denote the direction of the current, then the thumb points in the direction of the north pole.
Using this technique, we understand that the side A has the south pole as the current is in the clockwise direction.
The required direction of current and the pole of magnetic field at B is therefore anticlockwise and has the north pole.

So, the correct answer is “Option C”.

Note:
We can remember the poles associated with the direction of current very easily for future reference. The anticlockwise direction of current always represents that the north pole is at the end of the coil and the south pole is associated with the clockwise direction of current.