Answer:
(a) The change in magnetic flux is equal to the product of the magnetic field strength, the area of the coil, and the cosine of the angle between the magnetic field and the surface of the loop. Therefore, the change in magnetic flux is equal to 0.200T x (π x (25.0cm)^2) x cos(45°) = 7.85 x 10^-3 Tesla-square meters.
(b) The induced emf is equal to the change in magnetic flux divided by the time taken for the change to occur. Therefore, the induced emf is equal to 7.85 x 10^-3 Tesla-square meters / 0.250s = 3.14 Volts.