JEE Main20203 Sep 2020Evening ShiftPhysicsCurrent ElectricityActual
A galvanometer coil has 500 turns and each turn has an average area of 3 × 10 - 4 m 2 . 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 _________ .
Correct answer
0
Step-by-step solution
τ = M → × B → = NiAB   sin 90 ° = NiAB = Ni   S   B ⇒       B = τ NiS = 1 . 5 500 × 0 . 5 × 3 × 10 - 4 = 20