JEE Main 2019PhysicsMagnetic Effects of CurrentEasyMCQ

JEE Main 2019 — Magnetic Effects of Current Question with Solution

JEE Main 2019 (10 Apr Shift 2)

Question

The magnitude of the magnetic field at the centre of an equilateral triangular loop of side 1 m which is carrying a current of 10 A is:

[Take  μ0=4π×10-7 N A-2 ]

Choose an option

Show full solutionCorrect option: C
Correct answer
C18 μT

Step-by-step explanation



The perpendicular distance of centroid from any side, 123 m
Magnetic field due to one side.
B1=µoI4πr[cosθ1+cosθ2]
=μ0(10)4πr123cos30°+cos30°
=53π μ0 32+32=15μ0π
Net magnetic field B=3B1=45πμ0=45π×4π×10-7
=180×10-7 T
=18 μT

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About this question

This is a previous-year question from JEE Main 2019, covering the Magnetic Effects of Current chapter of Physics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.