The magnetic flux through each loop of a 75-loop coil is given by (8.8t−0.51t3)×10−2t⋅m2, where the time t is in seconds.

To determine the emf as the function of time emf of the coil which is induced is
E = -NdФ/dt
= -(75) d/dt ((8.8-0.5Lt³) × 10⁻²)
=-(75) (8.8-0.51(3+2)) ₓ 10⁻²
=-6.6 + 1.15t²) V
The value of t = 1.1s and t= 3.15
t = 1.1s, where induced emf is
E = (-6.6 +1.15 (1.1)²)
=-5.23V
At t= 3.1s, where induced emf is
E = (-6.6 +1.15(3.1)²)
=4.45V

Ibelieve the answer is b