Question

State clock rule to determine the polarity of any face of a circular current loop.

Answer 1

Hint: As the name suggests in the problem “Clock rule”, it is a trick rule which helps us find the polarity of a current carrying loop if the direction of current is known and vice versa. We will first analyze the direction of current with respect to the direction in which a clock can move, that is clockwise or counterclockwise. As a clock can move in only these two directions, the Clock rule easily helps us find the polarity of the circular current loop as there are only two magnetic polarities, the North pole and the South pole.

Complete answer:
The clock rule states that, if in a current loop the current is moving in the direction of the clock, that is, clockwise , the magnetic polarity of that current loop is found to be the South Pole.
And, if the current in the loop is moving in the direction opposite to that of the clock, that is, in the counterclockwise direction, the magnetic polarity of that current loop is found to be North Pole.
This can be explained by the given diagram:

Here, we can clearly see that polarity of a current loop can be very easily determined using the clock rule.

Note:
These are some very short basic principles from the chapters of Electricity and Magnetism. They are not only used in solving these short type questions but are widely used in problems that generally consist of Solenoid and Toroid or any problem containing a magnetic loop within itself, which needs to be solved.