Electromagnetic Spectrum

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Introduction to Electromagnetic Spectrum

EM is a short-form that stands for the electromagnetic spectrum. The possibility of the appearance of electromagnetic waves is when both an electric field and a magnetic field come close. 

Some physicists explain that electromagnetic waves are the collection of oscillating magnetic and electric fields. You can find solutions to electromagnetic waves if you analyze Maxwell’s equations. They are called the fundamental equations of electrodynamics. 

You will know in brief regarding the electromagnetic spectrum in this article.

Note: The formation of electromagnetic waves is quite interesting. When a charged particle is in motion, it produces a magnetic field around its perimeter. The magnetic field direction varies with the types of charges. Positive charges have produced the field in the direction of acceleration, whereas negative charges have been the opposite. 

Types of Electromagnetic Waves

You must have heard of different names of electromagnetic waves. Well, the uses of these waves are very common and significant in many divisions.

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These types of waves are used to broadcast the signals for radio and television. This wave has the longest wavelength.


These electromagnetic waves are in the use of cooking, radar, telephone, and other signals.


This wave is beneficial for transmitting heat from the sun, radiators, and fire.

Visible Light

We can see with the help of visible light. 


Ultraviolet radiation is coming from the sun or many nuclear plants. This wave is not good for the skin sometimes. Scantiest use this radiation in fluorescent tubes.


This ray helps to get the visuals of organs and other parts. This technology is widely applicable in medical sciences.

Gamma Rays

  • Gamma rays are useful for killing cancer cells. 

  • The ray is propagated to infected regions. 

  • This wave has the shortest wavelength.

Concepts of Electromagnetic Spectrum Wavelengths

In 1888, Heinrich Hertz had verified a wave that had a speed of visible light. They are called radio waves in the present. The electromagnetic spectrum is responsible for measuring reflection, diffraction, refraction, and polarization.

All of the above properties of visible light can be studied through Maxwell’s waves. Visible light is the best example of the learning of electromagnetic waves. Scientists do not find any theoretical explanation for Electromagnetic Spectrum Wavelengths. 

However, they have parted the spectrum into different regions based on historical developments.

The following figure is the narrow range of visible light in the form of the electromagnetic spectrum.

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Spectrum of Wavelengths

Physicists have categorized electromagnetic waves into certain groups based on their frequencies f. 

The wavelength of the electromagnetic wave is equal to λ = c/f. ~400 nm to ~700 nm is the wavelength of visible light whereas ~400 nm is the wavelength of violet light. Its frequency is ~7.5*1014 Hz.

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In the full electromagnetic spectrum, visible light has a small part. The following table shows the frequency range and wavelength range of certain electromagnetic waves.

Type of Radiation

Frequency Range (Hz)

Wavelength Range


1020 - 1024

< 10-12 m


1017 - 1020

1 nm - 1 pm


1015 - 1017

400 nm - 1 nm


4 - 7.5*1014

750 nm - 400 nm


1*1014 - 4*1014

2.5 μm - 750 nm


1013 - 1014

25 μm - 2.5 μm


3*1011 - 1013

1 mm - 25 μm

radio waves

< 3*1011

> 1 mm

The Electromagnetic Spectrum

The electromagnetic spectrum definition is very simple. This is the range of all varieties of electromagnetic radiation. Radiation is a type of energy that passes and spreads out to certain areas until the energy level falls to zero. For example, visible light. 

Let’s consider the light coming out of a candle has a certain amount of electromagnetic radiation. Also, radio waves that travel to the sky have some amount of electromagnetic radiation.

FAQ (Frequently Asked Questions)

Q1. Which Colour has the Peak and Bottom Frequency Value?

Ans: It is violet which has a peak frequency value. You can find this colour in visible light. Also, it has the highest energy. On the other hand, red has finished at the bottom in the frequency value. Also, red has the least amount of energy.

Q2. Explain the Facts Behind the Red Sunset.

Ans: During the sunset, the light coming out of the sun passes through a long column or path length of the atmosphere of the surface of the earth. At this moment, the blue components available in the atmosphere help reduce the intensity of the sunlight. This helps the transmitted beam of sunlight to turn reddish or yellowish.

Q3. Mention Some Use of Electromagnetic Waves in Our Day-to-day Life.

Ans: We are using many things in our daily lifestyle that are based on electromagnetic radiation. We use these things which artificially bring forth electromagnetic waves:

  • Microwave ovens

  • Radar waves

  • Televisions

  • Radio stations

  • Heaters, and so on.

Q4. Find the Value of the Wavelength of an Electromagnetic Wave that is Traveling at a Frequency of 1.5 * 10¹⁴.

Ans: We know that, wavelength λ = c/f

So, if we put the value, we get λ = (3.00 x 10⁸ m/s) / (1.5 x 10¹⁴ 1/s) = 2.00 x 10⁻⁶ m