Explain in detail the four different types of oscillations.

Explanation

(i) Free oscillations : When the oscillator oscillates with a frequency that is equal to the natural frequency of the oscillator. Such an oscillation or vibration is known as free oscillation or free vibration.
Eg: (a) Oscillation of a simple pendulum,
(b) Vibration in a stretched string.
(ii) Damped oscillation : If an oscillator oscillates in a resistive medium, then its amplitude goes on decreasing. The energy of the oscillator is used to do work against the resistive medium. The motion of the oscillator is said to be damped oscillation.
Eg: (a) The oscillations of a pendulum (incluiding air friction) or pendulum oscillating inside an oil filled container.
(b) Electromagnetic oscillations in a tank circuit.
(iii) Forced oscillations : In this type of vibration, the body excuting vibration initially vibrates with the frequency of the applied periodic force. Such vibrations are known as forced vibrations.
Eg : Sound boards of stringed instruments.
(iv) Maintained oscillations : The amplitude of the oscilation can be made constant. By supplying energy from an external source. Such oscillations are known as maintained oscillations.
Eg : the vibration of a tuning fork gettting energy from a battery or from external power supply.