Torque produced in a moving coil galvanometer is, τ=BINAsinϕ.
Let torsional constant of the suspension wire be C, then Cθ=BINAsin90∘
⇒C=θBINA=0.050.01×10×10−3×100×2×10−4
=4×10−5N−m/rad.
Therefore, x=4.
JEE Main 2024 — Physics Electromagnetism
A moving coil galvanometer has 100 turns and each turn has an area of 2.0cm2. The magnetic field produced by the magnet is 0.01T and the deflection in the coil is 0.05 radian when a current of 10mA is passed through it. The torsional constant of the suspension wire is x×10−5N−m/rad. The value of x is ______ .
Held on 1 Feb 2024 · Verified 6 Jul 2026.
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