Explain the direction of magnetic field around the straight conductor carrying current

Procedure :

  1. Take a plant and make a hole and place it on table.
  2. Place a stand on the place and suspend a copper wire from the stand and see that it passes through the hole made to the plank.
  3. Connect a battery and switch to this wire in series. Place some magnetic needle at the hole.
  4. If the current is passed through the wire, the magnetic needle deflects and it is directed as the tangent to the circle.
  5. If the current flows in downward direction, the field lines are in anti-clokwise direction and if the current flows in upward direction, the field lines are in clock-wise direction.

  1. The direction of the current and magnetic lines of force can be easily explained with the help of right hand thumb rule. If you hold the current carrying conductor with your right hand grip of sketching the thumb, the direction of the thumb shows the direction of the current, the direction of the other four fingers shows direction of magnetic lines of force.