Wavefront and Wave Normal – Class 12 | Chapter – 10 | Physics Short Notes Series PDF for NEET & JEE

Wavefront and Wave Normal: Wavefront and wave normal are two concepts related to the propagation of waves. Both the wavefront and the wave normal are important concepts in the study of wave propagation. They can be used to describe the behavior of waves, such as reflection, refraction, and interference, and they can be used to calculate the direction and speed of wave propagation. In addition, the wavefront and wave normal are related to the frequency and wavelength of a wave, which are fundamental properties of waves.

A wavefront is a surface that connects all the points of a wave that are in phase with each other. In other words, it is a surface of constant phase. For example, in a plane wave, the wavefront is a plane, while in a spherical wave, the wavefront is a sphere. The wavefront of a wave represents the shape of the wave at a given instant in time.

The wave normal is a line that is perpendicular to the wavefront at each point. It represents the direction of propagation of the wave. In other words, the wave normal points in the direction that the wave is moving. The angle between the wave normal and the surface over which the wave is propagating is known as the angle of incidence. The angle of reflection is the angle between the wave normal and the reflected wave.

Wavefront and Wave Normal

Wavefront

A wavefront is a surface that connects all the points of a wave that are in phase with each other. In other words, it is a surface of constant phase. For example, in a plane wave, the wavefront is a plane, while in a spherical wave, the wavefront is a sphere. To understand this concept, imagine dropping a stone into a still pond. The stone creates a circular ripple pattern that propagates outwards from the point of impact. At any given instant, the circular wavefront represents the shape of the wave. The wavefront is a surface that is perpendicular to the direction of wave propagation and connects all the points of the wave that are in phase with each other. In other words, all the points on the wavefront are vibrating in unison.

Wavefronts are used to describe the behavior of waves, such as reflection, refraction, and interference. For example, when a wavefront encounters a boundary between two different media, such as air and water, it can change direction and shape. This change in direction is known as refraction. When two or more wavefronts intersect, they can interfere with each other, creating regions of constructive and destructive interference.

Wavefronts can also be used to calculate the direction and speed of wave propagation. For example, the velocity of a wave is equal to the product of its wavelength and frequency. By measuring the distance between successive wavefronts, one can determine the wavelength of the wave, and by measuring the time it takes for the wavefronts to pass a given point, one can determine the frequency of the wave.

Wave Normal

The wave normal is a line that is perpendicular to the wavefront at each point. It represents the direction of propagation of the wave. In other words, the wave normal points in the direction that the wave is moving.

The wave normal is an important concept in the study of wave propagation. It can be used to calculate the direction and speed of wave propagation. For example, in a uniform medium, the wave normal is parallel to the direction of wave propagation, and the speed of the wave is constant. However, when a wave encounters a boundary between two different media, such as air and water, the wave normal can change direction, causing the wave to refract.

The angle between the wave normal and the surface over which the wave is propagating is known as the angle of incidence. The angle of reflection is the angle between the wave normal and the reflected wave. The angle of refraction is the angle between the wave normal and the refracted wave.

The wave normal is also related to the frequency and wavelength of a wave, which are fundamental properties of waves. The wavelength of a wave is the distance between successive wavefronts, while the frequency is the number of wavefronts that pass a given point per unit time. The wave normal can be used to calculate the speed of the wave using the formula v = fλ, where v is the speed of the wave, f is the frequency, and λ is the wavelength.


JOIN OUR TELEGRAM CHANNELS
Biology Quiz & Notes Physics Quiz & Notes Chemistry Quiz & Notes

Follow on Facebook

By Team Learning Mantras