Answer
(a) The current flows clockwise around the loop.
(b) No current is induced around the loop.
(c) The current flows counter-clockwise around the loop.
Work Step by Step
(a) As the magnetic field increases, there is more magnetic flux going through the loop. By Lenz's law, a current is induced around the loop which opposes the change in flux. Then, the current must produce a magnetic flux directed into the page. By the right hand rule, this current flows clockwise around the loop.
(b) Since the magnetic field is constant, there is no change in magnetic flux going through the loop. By Lenz's law, no current is induced around the loop.
(c) As the magnetic field decreases, there is less magnetic flux going through the loop. By Lenz's law, a current is induced around the loop which opposes the change in flux. Then, the current must produce a magnetic flux directed out of the page. By the right hand rule, this current flows counter-clockwise around the loop.
