Q. A coil of resistance 400 Ω is placed in a magnetic field. If the magnetic flux φ (Wb) linked with the coil varies with time t (s) as φ = 50t² + 4, the current in the coil at t = 2 s is
A) 1 A
B) 0.5 A
C) 0.1 A
D) 2 A
Explanation
[Solution from source] Induced emf e = dφ/dt = 100t, which is 200 V at t = 2 s. Current = e/R = 200/400 = 0.5 A. The constant 4 in φ does not contribute to the emf. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.