Question

Assertion (A): The deflection of a compass needle placed near a current carrying wire decreases when the magnitude of an electric current in the wire is increased.
Reason (R): Strength of the magnetic field at a point due to a current carrying conductor increases on increasing the current in the conductor.

• A. Both (A) and (R) are true and (R) is the correct explanation of (A).
• B. Both (A) and (R) are true, but (R) is not the correct explanation of (A).
• C. (A) is true, but (R) is false.
• D. (A) is false, but (R) is true.

Answer 1

The Correct Option is D

Step 1: Analyze the Assertion (A)
Assertion (A): The deflection of a compass needle placed near a current-carrying wire decreases when the magnitude of an electric current in the wire is increased.
This statement is false because when the current in the wire is increased, the magnetic field around it becomes stronger. As a result, the deflection of the compass needle should increase, not decrease.

Step 2: Analyze the Reason (R)
Reason (R): Strength of the magnetic field at a point due to a current-carrying conductor increases on increasing the current in the conductor.
This statement is true. According to the magnetic field rule for current-carrying conductors, the magnetic field strength is directly proportional to the current passing through the wire.

Step 3: Relationship between Assertion and Reason
The reason given is true, but it does not support the incorrect assertion.

Final Answer:
(A) is false, but (R) is true.