Q. 14.1 Which of the following examples represent periodic motion?
(a) A swimmer completing one (return) trip from one bank of a river to the other and bank.
(b) A freely suspended bar magnet displaced from its N-S direction and released.
(c) A hydrogen molecule rotating about its centre of mass.
(d) An arrow released from a bow
(a) The motion is not periodic though it is to and fro.
(b) The motion is periodic.
(c) The motion is periodic.
(d) The motion is not periodic.