The magnetic flux in a closed circuit of resistance 20 Ω varies with time t as Φ = 4t3 + 2t2 – 15t + 3. Calculate the magnitude of induced emf at t = 1s.

The magnetic flux in a closed circuit of resistance 20 Ω varies with

1.	The magnetic flux in a closed circuit of resistance 20 Ω varies with time t as Φ = 4t3 + 2t2 – 15t + 3. Calculate the magnitude of induced emf at t = 1s.
A.	3 V
B.	4 V
C.	5 V
D.	6 V
Answer» C.