JEE Advanced2018PhysicsMagnetic Effects of CurrentActual
A moving coil galvanometer has 50 turns and each turn has an area 2 × 10 - 4 m 2 . The magnetic field produced by the magnet inside the galvanometer is 0.02 T . The torsional constant of the suspension wire is 10 - 4 N m rad - 1 . When a current flows through the galvanometer, a full scale deflection occurs if the coil rotates by 0.2 rad . The resistance of the coil of the galvanometer is 50 Ω . This galvan
Correct answer
0
Step-by-step solution
n = 50 t u r n s A = 2 × 10 - 4 m 2 B = 0.02 T K = 10 - 4 Q m = 0.2 r a d R g = 50 Ω I A = 0 - 1.0 A τ = M B = C θ , M = N I A B I g N A = C θ 0.02 × I g × 50 × 2 × 10 - 4 = 10 - 4 × 0.2 I g = 0.1 A For galvanometer, resistance is to be connected to ammeter in shunt. I g × R g = I - I g S 0.1 × 50 = 1 - 0.1 S S = 50 9 = 5.55