An Adjustable Single Loop Positioned in the Plane of the Page

Multiple Choice

An adjustable single loop positioned in the plane of the page is placed in a magnetic field B = 1.5 T, making an angle of 30^o with the page. When the cross-sectional area of the loop is reduced from 0.50 m² to 0.35 m² in 0.30 s, the average emf induced in the coil is

A) 87 V.
B) 65 V.
C) 0.87 V.
D) 0.65 V.
E) 0.38 V.