Question

5. A circular loop in the plane of the page lies in a 0.5T magnetic field that is oriented into the page. The diameter of the loop changes from 20 cm to 8 cm in 0.5 s. Calculate: A. The direction of the induced current. (5 pts) B. The magnitude of the average induced emf. (5 pts) C. The average induced current if the coil resistance is 2.5 Q. (5 pts) 6. Calculate the direction of the current induced in the loop in the two examples shown below. A. A square loop of wire lies in the plane of the page. A decreasing magnetic field is directed into the page. (5 pts) B. You push a permanent magnet with its north pole away from you toward a loop of conducting wire in front of you and the north pole is about to enter the loop. (5 pts)

Answer 1

use lens law

Ans: a) As one can observe that diameter decreases, so, the magnetic flux througth the loop decreases. From lens law, it will oppose this change & produced an induced earl current such that it increases the magnetic flux. So, direction of current will be clockwise if magnetic field is into the page. e emf- e= d(BA) = B dA = BA[87-227 e=0.5x3.14x [100-16] 154 -0.02637 V 0.5 c) Induced current = v=0.0005 A Magnitude of emf = - alt at t