JEE Main 2020PhysicsCurrent ElectricityEasyNumerical

JEE Main 2020 — Current Electricity Question with Solution

JEE Main 2020 (03 Sep Shift 2)

Question

A galvanometer coil has 500 turns and each turn has an average area of 3×10-4m2. If a torque of 1.5 Nm is required to keep this coil parallel to a magnetic field when a current of 0.5A is flowing through it, the strength of the field (in T) is _________ .

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Show full solutionCorrect answer: 20
Correct answer
20

Step-by-step explanation

τ=M→×B→=NiAB sin90°

=NiAB=Ni S B

⇒   B=τNiS=1.5500×0.5×3×10-4=20

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About this question

This is a previous-year question from JEE Main 2020, covering the Current Electricity 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.