# 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?

• 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

• 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

### Resonance

• 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

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