MHT CET20255 May 2025Evening ShiftPhysicsElectromagnetic InductionActual
A coil having ' N ' turns and resistance ' R ' is connected to a galvanometer of resistance '6R' . The magnetic flux linked with this coil changes from ₁ weber to ₂ weber in time ' t ' second. The induced current in the circuit is
Options
- AN ( ₂- ₁ ) t
- BN ( ₂- ₁ ) 7 Rt
- CN ( ₂- ₁ ) Rt
- DN ( ₂- ₁ ) 6 R t
Correct answer
B. N ( ₂- ₁ ) 7 Rt
Step-by-step solution
The induced current I is determined by the induced EMF and the total circuit resistance. With coil resistance R and galvanometer resistance 6R in series, the total resistance is R_ total = R + 6R = 7R . Faraday's law gives the magnitude of induced EMF as | | = N ₂ - ₁ t for flux change ₂ - ₁ over time t . Applying Ohm's law yields I = | | R_ total = N( ₂ - ₁) 7Rt . Final answer: B