Question

how to determine direction of magnetic field right hand rule

Answer 1

If we place our right thumb in the direction of current then the curl of the finger represents the direction of magnetic field, like this

Answer 2

How to determine direction of magnetic field right hand rule?

If a current-carrying conductor is imagined to be held in a right hand such that the thumb point towards the direction of current, then the direction in which your finger curl around the conductor will give the direction of the field lines of the magnetic field.