Question

i want to know about "what is right hand thumb rule"

Answer 1

Assume that you are holding a straight current carrying conductor in your right hand such that the thumb points towards the direction of current. Then your fingers will wrap around the conductor in the direction of field lines of the magnetic field. Right Hand Thumb rule is also known as Maxwell's corkscrew rule.

Answer 2

To find the direction of magnetic field due to a straight current-carrying conductor, we use the Right Hand Thumb Rule which is as follows:

Imagine a straight conductor in your right hand such that the thumb points in the direction of current. The direction of curling of fingers of the right hand gives the direction of magnetic field lines.