MHT CET202615 April 2026Morning ShiftPhysicsElectromagnetic InductionActual
The coefficient of mutual induction is 3 H and induced e.m.f. across secondary is 4 kV. Current in primary is reduced from 7 A to 2 A. The time required for the change of current is
Options
- A3.75 10⁻³ s
- B2.5 10⁻³ s
- C4.5 10⁻³ s
- D3.5 10⁻³ s
Correct answer
A. 3.75 10⁻³ s
Step-by-step solution
The magnitude of induced e.m.f. in the secondary coil is given by |e| = M | I t | Substituting the given values: 4000 = 3 | 2 - 7 t | 4000 = 15 t t = 15 4000 = 3.75 10⁻³ s Answer: 3.75 10⁻³ s