The magnetic field at the centre of a current carrying circular loop of radius R is 16 μ T . The magnetic field at a distance x=√(3) R on its axis from the centre is \ \ \ \ μ T .

Physics · Moving Charges and Magnetic Field

JEE Main 2026 — 28 January, Morning Shift — Question 38

The magnetic field at the centre of a current carrying circular loop of radius $R$ is $16 \mu \mathrm{~T}$ . The magnetic field at a distance $x=\sqrt{3} R$ on its axis from the centre is $\_\_\_\_$ $\mu \mathrm{T}$ .

Option A:
$2 \sqrt{2}$
Option B:
4
Option C:
2
Correct
Option D:
8

Answer: C

Step-by-step solution

$\frac{\mu_{0} I}{2 R}=16 \mu \mathrm{~T}$ $\frac{\mu_{0} \mathrm{IR}^{2}}{2\left(\mathrm{x}^{2}+\mathrm{R}^{2}\right)^{3 / 2}}=\frac{\mu_{0} \mathrm{IR}^{2}}{2 \times 8 \mathrm{R}^{3}}=2 \mu \mathrm{~T}$

Answer key and solution verified before publishing.

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Exam: JEE Main 2026
Paper: 28 January, Morning Shift
Subject: Physics
Chapter: Moving Charges and Magnetic Field
Topic: Magnetic Field Due to Current-Carrying Wire - Biot-Savart Law