JEE Main 2022 · PhysicsMultiple choiceSingle correctEasyCalculation

JEE Main 28 July 2022, Shift 2, Physics Q13

Question 13 of 90 in this shift, Physics question 13 of 30, Section A.

The magnetic field at the center of current carrying circular loop is

\mathrm{B_1}

. The magnetic field at a distance of

\sqrt{3}

times radius of the given circular loop from the center on its axis is

\mathrm{B_2}

. The value of

\mathrm{B_1/B_2}

will be

(1)9 : 4
(2)12 : $\sqrt{5}$
(3)8 : 1Official answer
(4)5 : $\sqrt{3}$

Official answer

Option 3

NTA final key.

Chapter: Moving Charges and Magnetism
Topic: Biot-Savart Law
Idea tested: Ratio of Axial to Central Magnetic Field

Same idea in other shifts

Asked 5× in all

2 Apr 2025, Shift 1 · Q38Let $B_1$ be the magnitude of magnetic field at center of a circular coil of radius R carrying current I. Let $B_2$ be the magnitude of…EasySingle correct
8 Apr 2023, Shift 2 · Q59The ratio of magnetic field at the centre of a current carrying coil of radius $r$ to the magnetic field at distance $r$ from the centre…MediumNumerical value
24 Jun 2022, Shift 1 · Q49The magnetic field at the centre of a circular coil of radius r, due to current I flowing through it, is B. The magnetic field at a point…EasySingle correct
26 Aug 2021, Shift 1 · Q11The fractional change in the magnetic field intensity at a distance ‘r’ from centre on the axis of current carrying coil of radius ‘a’ to…MediumSingle correct

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.