Oscillations: What Are Oscillations, What Are the Three Main Types of Simple Harmonic Motion (For CBSE, ICSE, IAS, NET, NRA 2022)

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  • It is the repetitive variation, typically in time, of some measure about a central value (often a point of equilibrium) or between two or more different states.
  • The term vibration is precisely used to describe mechanical oscillation.

What Are Oscillations?

What Are Oscillations
  • It is a measure of some repetitive variation, as a function of time.
  • It can be measured with respect to a state of equilibrium.
  • Most common and simplest example for oscillation is the motion of a simple pendulum.

What Are the Three Main Types of Simple Harmonic Motion?

  • Three main types of simple harmonic motion in physics are
  • Free Oscillation
  • Forced Oscillation
  • Damped Oscillations

Free Oscillation

  • Amplitude and time period remains constant without any influence of external factors.
  • When the system has zero damping, the amplitude remains constant provided, this theory is possible in cases where damping always occurs.
  • To overcome external forces like air resistance or friction, the reduction in amplitude (energy loss of a system) is referred to as damping.
  • The amplitude, frequency, and energy all remain constant.

Forced Oscillation

  • When an external periodic force influences a body՚s oscillation, then it is called forced oscillation. Damping occurs in the amplitude of oscillation but remains constant with the help of the external energy supplied by the system.
  • As an example, constantly pushing a swing so that its oscillation doesn՚t reduce.

Damped Oscillation

Damped Oscillation
  • The reduction of the amplitude of an object with respect to time, such type of oscillations is known as damped oscillations.
  • The energy of a system decreases with the decrease in amplitude.
  • There are two types of damping:
  • Natural Damping
  • Artificial Damping


  • It is the phenomenon wherein an external vibrating system causes the oscillation of another system with higher amplitude at a particular frequency.
  • Frequency at that particular resonance level is known as a resonant frequency.
  • When tuning a guitar with the help of another guitar, the resonant frequency can be observed. In this case, the amplitude of the vibration of the string is the highest.
  • Reason for large amplitude oscillations generated at that resonant frequencies are as a result of vibrational energy that is accumulated in the system.
  • Resonance is of the following types
  • Mechanical
  • Acoustic
  • Orbital
  • Particle
  • Electrical
  • Optical Resonance