Transverse Nature of Electromagnetic waves

Introduction

Visible light is electromagnetic waves that enable us to view the world around us. The various electromagnetic waves include infrared rays, microwaves, gamma rays, and ultraviolet rays. Every wave has a distinctive characteristic, range of distinct frequency and wavelength, and different uses.

Maxwell was the first scientist to predict the presence of electromagnetic waves. These waves were produced and detected by Hertz. Another scientist called JC Bose created an electromagnetic range of wavelength between 5 and 25 millimetres. Marconi successfully transmitted electromagnetic waves up to a few kilometres.

Reflection

Reflection means a change in direction. A reflection of a wave can be defined as the change in the direction of a wave. 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:

1. Open boundary interface: When a wave strikes the interface of an open boundary, it will be reflected and refracted.
2. 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 hits a wall.

When a wave strikes a surface, it is known as incidence. The wave that strikes is called an incident wave. When an incidence wave strikes on a wall or a closed boundary, a complete reflection is called a reflected wave. Thus, when a wave’s incidence occurs, some parts are reflected, and some are transmitted into a second medium.

Absorption of wave

When a wave transfers its energy to the atoms or molecules, It causes vibration to molecules. This vibration absorbs some energy from the wave. This phenomenon is called the absorption of waves.

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.

Transverse Nature of Electronic Waves

In an electromagnetic wave, electric and magnetic field vectors are perpendicular to each other, and they are mutually perpendicular to the direction of propagation of the wave. This nature of electromagnetic waves is known as Transverse nature.

Polarisation

Polarisation is one of the properties of transverse waves 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 polarised light wave oscillates only in one direction, while the non-polarised wave can oscillate in multiple directions. The process of the transformation of the non-polarised waves into polarised waves is called polarisation.

There are three types of polarisation under the transverse and longitudinal wave motion:

Linear Polarisation

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

Circular Polarisation

Circular polarisation occurs with two linear components in the electric field perpendicular to each other such that their amplitudes are equal along with the phase difference of π/2.

Elliptical Polarisation

Elliptical polarisation occurs when the phase difference between the two linear components is not equal.

Diffraction

As we already know, light behaves both as a wave and 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 that show wave-like properties. 

We can observe many effects of diffraction in our day-to-day life. Involving light is the brightest example of diffraction. It can produce dark colourful bands and fringes of light.

Diffraction is an optical process with a regular pattern where the light splits or refracts into several beams that travel in different directions. Their directions depend on the spacing of the grating and the wavelength of the light.

Conclusion

Thus, by analysing the nature of light, we can conclude that it is of dual nature as it behaves like a wave and a particle. When a light wave with a single frequency strikes on a surface or system, some portion of the light wave is absorbed by the object’s surface, and the object transmits the rest. Diffraction also occurs here; when the light wave strikes at the edge of an object, it slightly bends. Transverse waves feature magnetic and electric field vectors that are perpendicular to each other, and at the same time, they are also perpendicular to the direction of wave propagation. They have many properties, and polarisation is the one that determines the direction of the oscillation. Some phenomena like reflection and transmission of light occur when the natural frequency of the light wave is not the same as the natural frequency of the vibration of the objects, i.e., the frequency at which an object tends to vibrate when it is hit, strikes, or somehow disturbed.