The square loop in the figure below is made of wires with a

The square loop in the figure below is made of wires with a total series resistance of 10.7 ?. It is placed in a uniform 0.140-T magnetic field directed perpendicular into the plane of the paper. The loop, which is hinged at each corner, is pulled as shown until the separation between points A and B is 3.00 m. If this process takes 0.120 s, what is the magnitude and direction of the average current generated in the loop? (Assume the magnetic field is directed into the page.) Answer is positive if current is counterclockwise, and negative if it is clockwise; magnitude should be in A.

Solution

given

R=10.7 Ohms

B=0.14 T

t=0.12 sec

distace between A and B is d=3 m

emf=B*dA/dt

emf=B*(A2-A1)/t

and

current i=emf/R

i=(1/R)*B(A2-A1)/t

i=(1/10.7)*0.14(A2-A1)/0.12

i=0.109*(A2-A1) Amperes

here figure is not given, and substitude A2-A1=change in Area from the figure and calculate current