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Transverse nature of electromagnetic waves

This article provides a straightforward explanation of the transverse nature of electromagnetic waves. It begins with a simplified explanation of electromagnetic waves and goes on to explain how these waves are transverse in nature.

An electromagnetic wave consists of an electric and a magnetic wave in which electric and magnetic field vectors are perpendicular to each other. Not only this, but they are also perpendicular to the direction of propagation of the wave. This nature of electromagnetic waves is known as the transverse nature of electromagnetic waves.

Reflection:

Reflection simply means a change in direction. Reflection can be of light and wave, both. A reflection of a wave can be defined as the change in the direction of a wave upon striking the interface between any two materials. When a wave strikes the interface of the surface of any two materials, some portion of the wave returns. Thus, this phenomenon of the bouncing back of a wave is known as a reflection of waves. 

The interface of the materials can be of two types :

  • Open boundary interface: When a wave strikes the interface of an open boundary, it will be reflected and reflected both.
  • Closed boundary interface: It is a rigid boundary. When a wave strikes on the interface of a closed boundary, the complete wave will be reflected. Such an incident takes place when the wave strikes a wall. 

When a wave strikes a surface, it is known as incidence. The wave that strikes is called an incident wave. Thus, when an incidence of a wave takes place, some parts of the wave are reflected, and some of its parts are transmitted into a second medium. When an incidence wave strikes on a wall or a closed boundary, there is a complete reflection of the wave, and the wave is called a reflected wave. 

There are two types of reflection: fixed end reflection and free end reflection. In a fixed end reflection, the incidence wave comes back upside down while the wave encountering a free end comes back the same way it went out.

Polarization: 

Polarization is one of the properties of transverse waves, which is associated with the geometrical orientation of their oscillations. In other words, it is the property of transverse waves which tells about the direction of their oscillations. A polarized light wave oscillates only in one direction, while the non-polarized wave can oscillate in multiple directions. The process of the transformation of the non-polarized waves into polarized waves is called polarization. 

There are three types of polarization in accordance with the transverse and longitudinal wave motion.

Linear polarization: 

When the electric field of light is limited to a single plane with the direction of propagation, it is known as linear polarization.

Circular polarization:

Circular polarization takes place with two linear components in the electric field, which are perpendicular to each other such that their amplitudes are equal along with the phase difference of π / 2.

Elliptical polarization:

Elliptical polarization takes place when the phase difference between the two linear components is not equal.

Diffraction:

As we already know, light behaves both as a wave and as a particle. When it strikes the surface of any object, many phenomenons take place together. Diffraction is one of them. It takes place when an incidence wave encounters an obstacle or object. It can be defined as the bending of the striking wave at the corner of the objects.

In other words, it is the slight bending of a wave at the edge of an object. It takes place with sound, electromagnetic radiation, and many small moving particles like atoms, electrons, and neutrons as they show wave-like properties. It is the result of interference. It takes place when electromagnetic radiation takes place with a period structure. It is most pronounced when the wavelength of the radiation is about the same as the repeat distance of the periodic structure. 

We can observe many effects of diffraction in our day-to-day life. It can produce dark colorful bands and fringes of light. Involving light is the most colorful example of diffraction. Diffraction of particles is seen in our atmosphere when diffraction by these particles causes a bright ring which is visible around the bright light sources such as the sun and the moon.

Diffraction in an optical takes place with a regular pattern where the light splits or refracts into several beams which travel into different directions, and their directions depend on the spacing of the grating and the wavelength of the light.

Conclusion

Thus, by analyzing the nature of light, we can conclude that it is of dual nature as it behaves like both a wave and a particle. When a light wave, having a single frequency, strikes on a surface or system, it causes a number of phenomenons together. Some of the portions of the light wave are observed by the surface of the object, and some of its portions are transmitted by the object. Diffraction also takes place here when the light wave strikes at the edge of an object it slightly bends.

Transverse waves (featuring electric field and magnetic field vectors which are perpendicular to each other at the same time they are also perpendicular to the direction of the propagation of the wave) have many properties, and polarization is one of them which determines the direction of the oscillation.

Some phenomenons like reflection and transmission of light take place when the natural frequency of the light wave is not as same as the natural frequency of the vibration of the objects( the frequency at which an object tends to vibrate when it is hit, strikes, or somehow disturbed).