20. A 150-turn circular coil of wire (radius R = 20cm) is placed in a uniform B-field of B = 0.4T, which points along the axis of the coil. The

field is then steadily reduced to zero over a time interval of 350ms. What is the magnitude of the emf induced in the wire during this interval? A) 171V B) 7.5V C) 48.9V D) 21.5V E) 103V