A coil consists of 100 turns of wire wrapped around a square frame of sides 0.25 m. The coil is centered at the origin with each of its sides parallel to the x ?or y ?axis. Find the induced emf across the open-circuited ends of the coil if the magnetic field is given by (a) B = z 20 e ^-3t (T) (b) B = z 20 cos x cos 10^3 t (T) (c) B = z 20 cos x sin 2y cos 10^3 t (T)