Question

Assertion-Reason Type Question Assertion (A): The magnetic field at the center of a circular current carrying loop is directly proportional to the current flowing through it.
Reason (R): According to Biot–Savart’s law, magnetic field produced by a current element is proportional to the current element. Choose the correct answer from the options given below:

• A. Both Assertion and Reason are true and Reason is the correct explanation of Assertion.
• B. Both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
• C. Assertion is true but Reason is false.
• D. Assertion is false but Reason is true.

Hint:

Remember: \[ B_{\text{circular loop}}=\frac{\mu_0 I}{2R} \] Magnetic field increases with current and decreases with radius.

Answer 1

The Correct Option is A

Step 1: Recall Biot–Savart law. Magnetic field due to a current element is: \[ dB \propto I \] Hence magnetic field is directly proportional to current.

Step 2: Magnetic field at the center of circular loop. For a circular loop: \[ B=\frac{\mu_0 I}{2R} \] Thus: \[ B \propto I \] Hence Assertion is true.

Step 3: Check the Reason. Reason correctly explains why magnetic field depends on current. Therefore: \[ \boxed{\text{Both Assertion and Reason are true and Reason correctly explains Assertion}} \]