Procedure :
- Take a thin wooden plank and cover it with white paper.
- .Make two holes to the plank and pass a copper wire through the holes so that 4 to 5 wounds of copper wire makes it as a coil.
- The ends of the wire is connected to the battery terminals.
- Now place a compass needle at the centre of the coil.
- Put dots on either side of the compass. Repeat this by keeping at the dots. We can observe that field lines are circular.
- Here the direction of the field is perpendicular to the plane of the coil.
- The direction of the magnetic field due to coil points towards you when the current in the coil is in anti-clockwise direction.
- When you curl your right hand fingers in the direction of current, thumb gives the direction of magnetic field.