Question

With the help of a labelled circuit diagram, illustrate the pattern of the magnetic field lines of the magnetic field produced around a straight current carrying conductor. Explain how, with the help of right-hand thumb rule, we can determine and mark the direction of magnetic field lines due to a current.

Hint:

Use right-hand thumb rule for direction: thumb = current, fingers = field lines.

Answer 1

Pattern: The magnetic field lines around a straight current carrying conductor are concentric circles centered on the wire. The strength of the field decreases as the distance from the wire increases. 
Right-Hand Thumb Rule: If you hold the conductor in your right hand such that the thumb points in the direction of the current, then the curled fingers show the direction of the magnetic field lines.