Electromagnetic Spectrum, Practice Problems, FAQs

We can see the world around us thanks to electromagnetic waves in the form of visible light. Our surroundings are warmed by infrared rays. Our favourite TV and radio shows are broadcast over the airwaves, and the list goes on. We'll look at electromagnetic waves and their spectrum in this post. The electromagnetic spectrum, in basic terms, is the range of all types of electromagnetic radiation.

Table of Contents

History of Electromagnetic Waves
Electromagnetic Spectrum
Electromagnetic Waves In Spectrum
Uses of Electromagnetic Waves
Practice Problems
FAQs

History of Electromagnetic Waves

Maxwell was the first scientist to anticipate that electromagnetic waves would exist.
Hertz: He experimented with producing and detecting electromagnetic waves with a wavelength of 6 m.
J.C. Bose created electromagnetic waves with wavelengths ranging from 5 to 25 millimetres.
Marconi: He was able to successfully transmit electromagnetic waves over a distance of a few kilometres. When one of the spark gap terminals is linked to an antenna and the other terminal is earthed, Marconi discovered that the EM waves produced may travel up to several kilometres.

Electromagnetic Spectrum

The electromagnetic spectrum ranges to a wide spectrum that includes a set of frequencies, wavelengths and also the photon energies which span from even below to over , corresponding to wavelengths ranging from a few kilometres to a fraction of the size of a nucleus of an atom. In a vacuum, electromagnetic waves move at speeds that are similar to those of light. However, they do so over a wide range of wavelengths, frequencies considering the wave characteristics and photon intensities considering the particle characteristics of light. Electromagnetic waves were predicted by Maxwell, but they were discovered experimentally by Hertz. Electromagnetic waves comprise (i) -rays, (ii) X-rays, (ii) ultraviolet rays, (iv) visible light, (v) infrared, (vi) microwaves, and (vii) radio waves, as we now know.

The electromagnetic spectrum is the orderly dispersion of electromagnetic radiations according to their frequency (or wavelength). There is no visible distinction between one wave and the next. The categorization is dependent on how these waves are generated and/or detected, in general.

Electromagnetic Waves In Spectrum

In increasing order of frequency and decreasing order of wavelength, radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays, gamma rays, and cosmic rays constitute the complete range of the electromagnetic spectrum. The kinds of radiation, as well as their frequency and wavelength ranges, are as follows:

The electromagnetic spectrum is shown in the diagram below:

Uses of Electromagnetic Waves

Radio waves are received via a radio, which is a device that receives radio waves transmitted by radio stations. Radio waves can be sent into space. Radio waves are mostly used for television broadcasting, military communications and mobile-satellite communication.
Microwave: Microwaves produce this type of radiation, which is useful for cooking at home or at the office. It is used by astronomers to deduce and interpret the structure of nearby planets or even galaxies and stars.
Infrared light is a kind of light often used in night vision goggles. The infrared light emitted by living animal skin and heated objects may be captured, read and analysed by these specific devices. Interstellar dust is tracked in space using infrared light.
X-ray: X-rays are in handy in a number of scenarios. A doctor, for example, can use x-ray equipment to take pictures to check the conditions of bones or teeth. Airport security personnel use it to scrutinise and check bags. Heated gases in the universe also release X-rays.
The gamma-ray has a variety of medical uses. Gamma-ray imaging is a type of imaging process that allows us to have a glimpse within our bodies. To our utter surprise, the cosmos is the biggest gamma-ray generator in the universe.
Ultraviolet radiation is emitted mostly by the stars (so the sun). It causes burns and tans in the skin. In space, UV light is released by heated materials.
Visible Light: This spectrum can be seen with our naked eye. Light bulbs, LED lighting, stars, and other things emit radiation in the range of visible light spectrum.

Practice Problems

Q 1. Which of the following is not an electromagnetic wave property?

a. Momentum
b. Energy
c. Heat Energy
d. Pressure

A. It is possible to provide motion to the material with which EM waves interact (and angular momentum). Electromagnetic waves transport energy. Electromagnetic waves are the only waves capable of transmitting energy across a vacuum. The pressure exerted by EM radiation may be detected with a radiometer. The panels, which are black on one side and white on the other, rotate due to pressure changes caused by light. Although EM waves do not carry thermal energy, any absorbed EM radiation can heat an object. So option (c) is correct.

Q 2. Can X-rays and gamma rays be used to broadcast radio/TV/mobile signals?
A. No, X-rays and gamma rays have a limited action range. Furthermore, they are dangerous and have a penetrating impact on the materials they come into touch with, as well as the potential to harm living bodily tissues.

Q 3. What are the sources of electromagnetic waves?
A. Electromagnetic waves are created by periodic fluctuations in electric or magnetic fields. Electric and magnetic field oscillations are synchronised in the waves generated.

Q 4. Which of the following parameters may be used to characterise the location of an electromagnetic wave within the electromagnetic spectrum?

a. Time
b. Wavelength
c. Frequency
d. Both b and c

A. Wavelength or frequency can be used to characterise the location of an electromagnetic wave within the electromagnetic spectrum. So option (d) is correct.

FAQs

Q 1. What is the highest frequency component of the electromagnetic spectrum?
A. Gamma rays have the shortest wavelength and the highest frequency.

Q 2. Which part of the electromagnetic spectrum contains the least energy?
A. Radio waves have the smallest frequency and hence the smallest amount of energy.

Q 3. What is the longest wavelength in the electromagnetic spectrum?
A. The electromagnetic spectrum is a collection of waves that occur in a certain order. The frequency of radio waves is the greatest, while the wavelength of gamma rays is the shortest.

Q 4. On the electromagnetic spectrum, where does visible light fall?
A. Between infrared and ultraviolet radiation, visible light is found in the electromagnetic spectrum. It has a frequency of about .