Two bar magnets are placed in a Vibration Magnetometer and allowed to vibrate. They make 20 oscillations per minute when their similar poles are on the same side and they make 15 oscillations per minute with their opposite poles lie on the same side. The ratio of their moments is :
(a) What is a vibration (or an oscillation)? Define 'amplitude' of vibration of an object.
(b) What is the frequency of a vibrating body whose time-period is 0.05 second ?