Question

As shown in the figure, a wire and a 10-2 resistor are used to form a circuit in the shape of a square, 20 cm by 20 cm. A uniform but nonsteady magnetic field is directed into the plane of the circuit. The magnitude of the magnetic field is decreased from 1.2 T to 0.4 T in a time interval of 72 ms. The average induced current and its direction through the resistor, in this time interval, are closest to 4 20 cm x x X x x X x x X 20 cm 102 27 mA, from a to b. 67 mA, from a to b. 27 mA, from b to a 44 mA, from b to a 44 mA, from a to b.

Answer 1

20cm 20m X x x x 10 a magnetic field decreased B = 1. 2T to B=0.4T in time At=&2 ms. - 77x108 change in magnetic field a ABF B-B1=-0.8T area (A) = 0.2X0.2 = 0.04 m2. Rate of change of flux ABIA - G. 444 Tma at S so induced emf, ha do – 0.4uy at = -0.4 uur So cutcrtcent CIJE E = -0.044 A & uima 0 uumA Ato B choose last option.