Question

What is Maxwell’s corkscrew rule? For what purpose is it used?

Answer 1

Hint:Maxwell’s corkscrew rule describes the relationship between the direction of the electric current and that of the magnetic field lines associated with it. As the name suggests the direction in which the screw moves and the direction in which its handle rotates or turns correspond to the directions of the current and the field lines.

Complete step by step answer.
Step 1: Based on the movement of the corkscrew describe Maxwell’s corkscrew rule.
It is well known that a varying electric field generates a magnetic field and a varying magnetic field generates an electric field. The direction of the electric current and that of the magnetic field lines are perpendicular to each other.
Consider a corkscrew being used to open a sealed bottle. As the corkscrew moves inwards, it rotates in the clockwise direction. Now the direction in which the corkscrew moves is taken to be the direction of the electric current and the direction of the handle is taken to be the direction of the magnetic field lines. This is shown in the figure below.

This rule is used for determining the direction of the magnetic field lines if the direction of the electric current is known. Similarly, it can be used to determine the direction of the electric current in a conductor if the direction of the magnetic field lines associated with the current-carrying conductor is known.

Note:Maxwell’s corkscrew rule is identical to the right-hand thumb rule in which the direction in which the right thumb points is taken as the direction of the electric current in a current-carrying conductor and the direction in which the fingers curl around the thumb is taken as the direction of the magnetic field lines.