W=MB(cosθ1−cosθ2)
When it is rotated by angle 180o then θ1=0∘ and θ2=180∘
W=2MB
W=2(NIA)B
=2×250×85×10−6[1.25×2.1×10−4]×85×10−2
=9.1μJ
NEET UG 2017 — Physics Electromagnetism
A 250-Turn rectangular coil of length 2.1cm and width 1.25cm carries a current of 85μA and subjected to a magnetic field of strength 0.85T. Work done for rotating the coil by 180∘ against the torque is:
Held on 30 Apr 2017 · Verified 9 Jul 2026.
9.1μJ
4.55μJ
2.3μJ
1.15μJ
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