Waves: Types of Waves, Wavelength of a Wave, Time Period of Oscillation (For CBSE, ICSE, IAS, NET, NRA 2022)

Get top class preparation for JEE right from your home: fully solved questions with step-by-step explanation- practice your way to success.

Wave, propagation of disturbances from place to place in a regular and organized way.


Propagation of Disturbances for Regular & Organized Way
  • Most familiar are surface waves that travel on water, but sound, light, and the motion of subatomic particles all exhibit wavelike properties.
  • In the simplest waves, the disturbance oscillates periodically with a fixed frequency and wavelength.

Types of Waves

There are four types of waves as given below:

Mechanical Waves

  • Which can exist in material media and follows Newton՚s laws.
  • A wave which needs a medium in order to propagate itself. Sound waves, waves in a Slinky, and water waves are all examples of this.

Transverse Waves

Transverse waves are referred to those whose particles oscillate in a perpendicular motion of the direction of propagation of the wave

Examples of Transverse Waves

  • Water waves (ripples of gravity waves, not sound through water)
  • Light waves
  • S-wave earthquake waves
  • Stringed instruments
  • Torsion wave

Longitudinal Waves

Longitudinal waves are referred to those whose particles oscillate along the way of the propagation of the wave

Examples of Longitudinal Waves

  • Sound waves
  • P-type earthquake waves
  • Compression wave

When the waves move from one point of the medium to another is called progressive wave.

Wavelength of a Wave

  • In the case of a progressive wave, the distance between two points in the same phase at that time period is known as the wavelength of a wave.
  • Distance is twice the number of two consecutive nodes and antinodes.

Time Period of Oscillation

When an element of a medium takes time to move through one complete oscillation then it is called time period.

Principle of Superposition of Waves

  • In a medium when multiple waves transverse simultaneously, the displacement is the algebraic sum of the displacements due to each wave.
  • This phenomenon is referred to as the principle of superposition.

Standing Waves

  • When two identical waves moving in opposite directions interfere, it results in a standing wave.
  • These waves are characterized by the zero displacement locations which are fixed and are called as nodes and locations of maximum displacements called as antinodes.

Doppler Effect

  • Change in the frequency of a wave when the source or the observer or both are moving relative to the medium.
  • So, this phenomenon is used in different scientific aspects such as planetary science wherein astronomers depend on this effect to identify planets exterior to the solar system.
  • This Effect is an increase (or decrease) in the frequency of sound, light, or other waves as the source and observer move towards (or away from) each other.