Answer:
The average emf induced in the loop is 0.25 V
Step-by-step explanation:
Given;
area of loop, A = 0.20 m²
strength of magnetic field, B = 50 mT
time, t = 40 ms

where;
Φ is magnetic flux, this is maximum when the plane of the loop is parallel to the magnetic field.
Φ = BA
induced emf = BA / t
induced emf = (50 mT x 0.20 m² ) / (40 ms)
induced emf = 0.25 V
Therefore, the average emf induced in the loop is 0.25 V