Question

A circular loop of wire lies in the plane of the paper. An increasing magnetic field points out of the paper. What is the direction of the induced current in the loop?


A) counter-clockwise
B) clockwise
C) counter-clockwise then clockwise
D) clockwise then counter-clockwise
E) There is no current induced in the loop.

Answer 1

B) clockwise

Explanation -

when a magnetic with (N pole facing) is stationary wrt coil far away - then say (p) lines are being enclosed by coil. it moves towards, distance reduces and say (2p) lines now go thro coil - flux changing and pole advancing - coil will build stronger * stronger induced current (making N-induced strong) to oppose.

This is also like the above. An increasing magnetic field is realized when current flow through a long wire and B at diff points on its axis have varying B with x.

Answer 2

B) clockwise

To induced emf is generated to negate the emf change by increasing magnetic field