JEE Main 2023 · PhysicsNumerical answerNumerical valueMediumCalculation

JEE Main 12 April 2023, Shift 1, Physics Q58

Question 58 of 90 in this shift, Physics question 28 of 30, Section B.

A conducting circular loop is placed in a uniform magnetic field of 0.4 T with its plane perpendicular to the field. Somehow, the radius of the loop starts expanding at a constant rate of 1 mm/s. The magnitude of induced emf in the loop at an instant when the radius of the loop is 2 cm will be _________

\mu

Official answer

NTA final key.

Chapter: Electromagnetic Induction
Topic: Faraday's Law
Idea tested: Faraday's Law Magnitude

Same idea in other shifts

Asked 15× in all

5 Apr 2026, Shift 2 · Q50A circular loop of radius 20 cm and resistance 2 $\Omega$ is placed in a time varying magnetic field $\vec{B}=(2t^2+2t+3)\ \mathrm{T}$ . At…EasyNumerical value
6 Apr 2026, Shift 2 · Q39A square loop of side 2 cm is placed in a time varying magnetic field with magnitude as $B=0.4\sin(300t)$ Tesla. The normal to the plane…MediumSingle correct
29 Jan 2024, Shift 1 · Q58A square loop of side 10 cm and resistance $0.7\,\Omega$ is placed vertically in east-west plane. A uniform magnetic field of $0.20\ T$ is…EasyNumerical value
31 Jan 2024, Shift 2 · Q58The magnetic flux $\phi$ (in weber) linked with a closed circuit of resistance $8\ \Omega$ varies with time (in seconds) as…EasyNumerical value
11 Apr 2023, Shift 1 · Q53The magnetic field B crossing normally a square metallic plate of area 4 m $^2$ is changing with time as shown in figure. The magnitude of…EasyNumerical valueHas a figure
25 Jul 2022, Shift 2 · Q60Magnetic flux (in weber) in a closed circuit of resistance 20 $\Omega$ varies with time t(s) as $\phi$ = 8t $^{2}$ - 9t + 5. The magnitude…EasyNumerical value
26 Jul 2022, Shift 2 · Q58In a coil of resistance 8 $\Omega$ ,the magnetic flux due to an external magnetic field varies with time as…MediumNumerical value
27 Jul 2022, Shift 2 · Q54A conducting circular loop is placed in X - Y plane in presence of magnetic field $\vec{B}=\left(3t^3\hat{j}+3t^2\hat{k}\right)$ in SI…MediumNumerical value

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.