JEE Main 2023 · PhysicsNumerical answerNumerical valueMediumCalculation

JEE Main 8 April 2023, Shift 2, Physics Q59

Question 59 of 90 in this shift, Physics question 29 of 30, Section B.

The 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 of coil on its axis is

\sqrt{x} : 1

. The value of

x

is __________

Official answer

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 3× 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
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

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 42 of the 174 JEE Main shifts held from 2017 to 2026.