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QJEEM20Ph188e: JEE Main 2020 Physics - Class 12 JEEM20Ph188e Solution: A galvanometer coil has 500 turns and each turn has an average…

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

Step-by-Step Verified Solution

Given N = 500

A = 3 ×\times 10–4 m2

τ\tau = 1.5 Nm

i = 0.5 A

We know, τ=BINA sinθ\tau = BINA\,sin\theta

1.5=B×0.5×500×3×10−41.5 = B \times 0.5 \times 500 \times 3 \times {10^{ - 4}}

B=10000500=20B = {{10000} \over {500}} = 20 Tesla

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