[Physics Class Notes] on Electromagnetic Spectrum Pdf for Exam

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 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. The direction of the magnetic field produced by the positive charge is opposite to the direction of the magnetic field produced by the negative charge.

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 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.

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. Scientists 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 has 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.

 

Properties of electromagnetic waves

• They are transverse.

• They have the oscillating electric and also magnetic vectors always at right angles which are in the direction of the propagation of the waves.

• They can travel well in a vacuum because they do not require a medium to travel.

• They travel at the speed of light.

• They are produced by the oscillating of the electric charges and also by the transition of electrons between the energy levels from the atom.

 

Applications of the Electromagnetic spectrum 

• Radio waves are transmitted through the air which does not cause damage even if it is absorbed by the human body.

• Microwaves are used in cooking. What happens is when the high-frequency microwaves get absorbed by the food molecules the heating is caused by the increase of the internal energy of the molecules.

• Fiber optic communication uses visible light.

• The sterilization of water using ultraviolet rays.

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.

 

Conclusion

This is all about the electromagnetic spectrum and its different forms. Determine the differences between these electromagnetic waves and learn their uses.