Question

What is the direction of magnetic field at the centre of a coil carrying clockwise current ?

• A. No direction
• B. normal to the axis of coil inwards.
• C. Along the axis of coil inwards.
• D. Along the axis of coil outwards.

Answer 1

The correct option is C Along the axis of coil inwards.

A solenoid is a long coil of wire wrapped in many turns. The magnetic field within a solenoid depends upon the current and density of turns. Its direction depends on the direction of the current. When a current passes through it, it creates a nearly uniform magnetic field inside or along the axis of the solenoid. Outside the coil or solenoid, that is, at the ends and beyond the magnetic field is small and appears to diverge.
When the current flows through the solenoid in the clockwise direction, then the magnetic lines of force inside or center of the coil will be along the axis inwards according to Fleming's right hand rule.

Hence Magnetic field at the centre of a coil carrying a clockwise current will be along the axis of coil inwards.