Question

A conducting coil lies flat on a level tabletop in a region where the magnetic field points straight up. The magnetic field suddenly grows weaker. When viewed from above, what is the direction of the induced current in this coil as the field decreases?

a) clockwise
b) counterclockwise
c) clockwise initially, then counterclockwise before stopping
d) there is no induced current in this coil because the field is gone

Answer 1

clockwise

Step-by-step explanation:

We shall apply Lenz's law to find the direction of induced current in case magnetic field changes. According to this law , direction of current induced is such that it will try to oppose the cause which produces the induced current .

In the present case, downward magnetic field decreases so current will be such that downward magnetic field increases . It can happen when clockwise current is induced. So clockwise current will be induced.