Question

The diagram below shows a magnetic kept just below the conductor AB which is kept in North South direction.

(i) In which direction will the needle deflect when the key is closed ?
(ii) Why is the deflection produced ?
(iii) What will be the change in the deflection if the magnetic needle is taken just above the conductor AB ?
(iv) Name one device which works on this principle.

Answer 1

(i) Eest direction
(ii) The needle align itself with the direction of magnetic field lines. Since the lines are perpendicular to the direction of current, the needle will try to allign that way also.
(iii) The northpole of the compass needle deflects towards West.
(iv) Electric motor