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Friday, 9 October

JEE Main 2021 · PhysicsMultiple choiceDiagram basedMediumMulti-step

JEE Main 16 March 2021, Shift 2, Physics Q5

Question 5 of 90 in this shift, Physics question 5 of 30, Section A.

The magnetic field in a region is given by B⃗=Bo(xa)k^\vec{B}=B_o\left(\frac{x}{a}\right)\hat{k}. A square loop of side d is placed with its edges along the xx and yy axes. The loop is moved with a constant velocity v⃗=voi^\vec{v}=v_o\hat{i}. The emf induced in the loop is :

The figure, in words

Square loop of side d in the x-y plane with its lower-left corner at the origin, edges along x and y axes; field B points out of the page (+z, dot symbol).
  1. (1)Bovod2a\frac{B_o v_o d}{2a}
  2. (2)Bovod2a\frac{B_o v_o d^2}{a}Official answer
  3. (3)Bovo2d2a\frac{B_o v_o^2 d}{2a}
  4. (4)Bovod22a\frac{B_o v_o d^2}{2a}

Official answer

Option 2

NTA final key.

Chapter
Electromagnetic Induction
Topic
Faraday's Law
Idea tested
EMF in Spatially Varying Fields

Same topic in other shifts

All Faraday's Law questions
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  2. 5 Apr 2026, Shift 2 · Q36A metal rod of length LL rotates about one end at origin with a uniform angular velocity ω\omega. The magnetic field radially falls off…HardSingle correct
  3. 5 Apr 2026, Shift 2 · Q50A circular loop of radius 20 cm and resistance 2 Ω\Omega is placed in a time varying magnetic field B⃗=(2t2+2t+3) T\vec{B}=(2t^2+2t+3)\ \mathrm{T}. At…EasyNumerical value
  4. 6 Apr 2026, Shift 2 · Q39A square loop of side 2 cm is placed in a time varying magnetic field with magnitude as B=0.4sin⁡(300t)B=0.4\sin(300t) Tesla. The normal to the plane…MediumSingle correct
  5. 8 Apr 2024, Shift 1 · Q60A square loop PQRS having 10 turns, area 3.6×10−3 m23.6\times10^{-3}\ \mathrm{m^2} and resistance 100 Ω100\ \Omega is slowly and uniformly being…MediumNumerical valueHas a figure
  6. 9 Apr 2024, Shift 2 · Q45A square loop of side 1515 cm being moved towards right at a constant speed of 22 cm/s as shown in figure. The front edge enters the 5050…EasySingle correctHas a figure

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. This question needs a figure we do not reproduce; it is described in words above. Lumi analyses 42 of the 174 JEE Main shifts held from 2017 to 2026.