Q 7

A 5-turn square loop (10 cm along a side,resistance = 4.0 )is placed in a magnetic field that makes an angle of 30 with the plane of the loop.The magnitude of this field varies with time according to B = 0.50t^{2},where t is measured in s and B in T.What is the induced current in the coil at t = 4.0 s?
A)25 mA
B)5.0 mA
C)13 mA
D)43 mA
E)50 mA

Q 8

A square coil (length of side = 24 cm)of wire consisting of two turns is placed in a uniform magnetic field that makes an angle of 60 with the plane of the coil.If the magnitude of this field increases by 6.0 mT every 10 ms,what is the magnitude of the emf induced in the coil?
A)55 mV
B)46 mV
C)50 mV
D)60 mV
E)35 mV

Q 9

A long straight wire is parallel to one edge and is in the plane of a single-turn rectangular loop as shown.If the loop is changing width so that the distance x changes at a constant rate of 4.0 cm/s,what is the magnitude of the emf induced in the loop at an instant when x = 6.0 cm? Let a = 2.0 cm,b = 1.2 m,and I = 30 A.
A)5.3 V
B)2.4 V
C)4.8 V
D)2.6 V
E)1.3 V