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Friday, 9 October

JEE Main 2021 · PhysicsMultiple choiceSingle correctMediumConceptual

JEE Main 18 March 2021, Shift 1, Physics Q12

Question 12 of 90 in this shift, Physics question 12 of 30, Section A.

A loop of flexible wire of irregular shape carrying current is placed in an external magnetic field. Identify the effect of the field on the wire.
  1. (1)shape of the loop remains unchanged
  2. (2)loop assumes circular shape with its plane normal to the fieldOfficial answer
  3. (3)loop assumes circular shape with its plane parallel to the field
  4. (4)wire gets stretched to become straight

Official answer

Option 2

NTA final key.

Chapter
Moving Charges and Magnetism
Topic
Magnetic Dipole Moment
Idea tested
Stable and unstable equilibrium states

Same topic in other shifts

All Magnetic Dipole Moment questions
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  3. 4 Apr 2026, Shift 2 · Q49A circular coil of radius 2 cm and 125 turns carries a current of 1 A. The coil is placed in a uniform magnetic field of magnitude 0.4 T.…EasyNumerical value
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  5. 3 Apr 2025, Shift 2 · Q36A magnetic dipole experiences a torque of 80380\sqrt{3} N m when placed in uniform magnetic field in such a way that dipole moment makes…EasySingle correct
  6. 6 Apr 2024, Shift 2 · Q58A coil having 100 turns, area of 5×10−3 m25\times10^{-3}\ \mathrm{m^2}, carrying current of 1 mA is placed in uniform magnetic field of 0.20 T…EasyNumerical 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 42 of the 174 JEE Main shifts held from 2017 to 2026.