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Question The diagram below shows a magnetic needle kept just below the conductor AB which is kept in North South direction.
(a) In which direction will the needle deflect when the key is closed?
(b) Why is the deflection produced?
(c) What will be the change in the deflection if the magnetic needle is taken just above the conductor AB?
(d) Name one device which works on this principle.
(a) North pole of needle deflects towards east.
(b) On passing current through the wire AB, a magnetic field is produced around the wire which aligns the magnetic needle in it's direction.
(c) The direction of deflection gets reversed i.e., now it deflects towards west.
(d) An electric bell works on this principle.