Question

The north pole of a long horizontal bar magnet is being brought towards a closed circuit consisting of a coil. The direction of induced current produced in it is

• A. anticlockwise
• B. horizontal
• C. vertical
• D. clockwise

Hint:

Remember the visual mnemonic letters N and S with directional arrows on their tips:
The tips of the letter N point Anticlockwise ($\circlearrowleft$).
The tips of the letter S point Clockwise ($\circlearrowright$).
Since an approaching North pole induces a North polarity face to repel it, the current must flow anticlockwise!

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
The question describes a situation where a magnetic north pole approaches a closed loop coil. We need to determine the directional sense of the resulting induced electric current.

Step 2: Key Formula or Approach:
This problem is solved using

Lenz's Law, which states that the direction of an induced current always opposes the change in magnetic flux that creates it.
$$\mathcal{E} = -\frac{d\Phi_B}{dt}$$ When a North pole approaches a face of a coil, the inward magnetic flux increases. To oppose this increase, the loop face must develop an opposing North pole magnetic field configuration to repel the incoming magnet.

Step 3: Detailed Explanation:
According to Lenz's Law, the loop face must generate its own magnetic fields pointing back outward to resist the approaching North pole. This requires the face of the coil to behave like a North pole.
Applying the standard

Right-Hand Grip Rule: for a face to exhibit a North magnetic pole, the electric current must circulate in a counter-clockwise or

anticlockwise direction. This matches option (A).

Step 4: Final Answer:
The direction of the induced current is anticlockwise, matching option (A).