A strong bar magnet is placed vertically above a horizontal wooden board. The magnetic lines of force will be:
(a) only in horizontal plane around the magnet
(b) only in vertical plane around the magnet
(c) in horizontal as well as in vertical planes around the magnet
(d) in all the planes around the magnet
When we place a magnet, it has magnetic lines of force in all the planes in its vicinity. Hence, the correct choice is (d).