Work done by the external force is equal to the change in the potential energy,
Wext=ΔU=Uf−Ui
⇒Wext=−MBcosθ2+MBcosθ1
⇒Wext=MB(cosθ1−cosθ2)
⇒Wext=14×10−5×2×105(cos0∘−cos60∘)
⇒Wext=14×2×21=14J
JEE Main 2022 — Physics Electromagnetism
A bar magnet having a magnetic moment of 2.0×105JT−1, is placed along the direction of uniform magnetic field of magnitude B=14×10−5T. The work done in rotating the magnet slowly through 60∘ from the direction of field is
Held on 26 Jun 2022 · Verified 6 Jul 2026.
14J
8J
4J
1.4J
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