Open In App

Radio Waves

Improve
Improve
Like Article
Like
Save
Share
Report

Radio waves are part of the electromagnetic spectrum and waves with one of the largest wavelengths. These waves are used for long-range communication as they are capable of propagating along the curvature of the earth. They are sent using the transmitter and are received using the antenna called the receiver. Radio waves are widely used for long-range communication and they operate in the range of 300 GHz to 3 kHz.

What are Radio Waves?

Radio waves are wave which is generated at the furthest end of the electromagnetic spectrum where the wavelength is highest they are transmitted using a radio transmitter and are received using a radio receiver. These waves can easily bend along the Earth’s curvature and are best suited for long-range communication. They do not get diffracted while travelling along the earth’s atmosphere. Similar to other electromagnetic waves radio waves also travel at the speed of light. They are generated by fast-accelerating electrons.

The image shows a man enjoying radio songs using radio waves.

Radio Waves

 

Radio Waves Formula

The formula which gives the relation between the speed, wavelength, and frequency of the radio waves is discussed below,

vr = λv

where,

  • vr is the speed,
  • λ is the wavelength, and
  • v is the frequency of the radio wave.

The concept of radio waves is explained by their speed formula. The speed of a radio wave is calculated by computing the product of its wavelength and frequency. 

  • It is denoted by the symbol vr. 
  • Its standard unit of measurement is meters per second (m/s). 
  • The dimensional formula of the speed of radio waves is given by [M0L1T-1].

Discovery of Radio Waves

James Maxwell was the first person to tell us about the behaviour of radio waves by studying Maxwell’s equation for electromagnetic waves. After him, the experiments on radio waves were demonstrated by Heinrich Hertz but they fail to provide the practical application of the radio waves. Italian scientist Guglielmo Marconi was the first to provide the practical implementation of radio waves and he created the first radio for which he was awarded the Nobel Prize in 1909. These waves were first used for commercial purposes in the 1900s. Radio waves are also called Hertzian waves.

Various objects in space emit radio waves as a part of their electromagnetic spectrum. The sun also emits radio waves which can be captured using radio telescopes which tells a lot about its structure, features, and others.

Wavelength of Radio Waves

The various wavelengths of the Radio waves are given in the following diagram.

Wavelength of Radio Waves

 

Radio Propagation

Radio waves propagate through space by radiation. When an electrical charge is accelerated, it generates a changing magnetic field, which in turn generates a changing electric field. These changing fields combine to form an electromagnetic wave that propagates through space.

Radio waves can travel through a vacuum, which means they can travel through space without any medium. However, radio waves can also travel through other materials, such as air, water, and various solid objects. The ability of radio waves to travel through these materials depends on their frequency and wavelength.

Wavelength, Speed, and Frequency of Radiowaves

Radio waves travel at a speed similar to the speed of light. Wavelength is the distance between two successive crests of the radio waves. These waves have the highest wavelength among all electromagnetic waves and conversely have the lowest wavelength.

The frequency range of the radio wave is from 3 kHz to 300 GHz.

Types of Radio Waves

Radio waves are of various types and some of the most common types of waves are,

  • Shortwave Frequency Range of Radio Waves
  • Low to Medium Frequency Range of Radio Waves
  • Higher Frequency Range of Radio Waves
  • Highest Frequency Range of Radio Waves

Shortwave Frequency Range of Radio Waves

Short radio waves use frequencies that come under the HF band of radio waves band, their wavelength varies from 1.7 megahertz to 30 megahertz. Some of these waves are used for telecommunication services.

Low to Medium Frequency Range of Radio Waves

These are the waves with a range of 535 kilohertz to 1.7 megahertz they are among the shortest waves in the radio wave band. They can easily travel underwater and can easily penetrate the rocks and thus, are widely used in underwater purposes, submarines, and mining and geothermal activities.

Higher Frequency Range of Radio Waves

Under these categories come the ranges HF, VHF, and UHF that are used by FM radio, which are used to communicate, public radio service, cellphones, and GPS. Frequency Modulation techniques are widely used by these frequency ranges of radio waves. to encode their information.

These waves transfer the information with the least disturbance and are used to send communication signals.

Highest Frequency Range of Radio Waves

The highest frequency range of radio waves is the SHF and EHF. They have some features of microwaves. They have very limited application and are mostly used for scientific purposes.

Radio Communication

Radio communication is one of the prime use of radio waves the AM or FM radio stations uses radio waves. In these FM radio antennas are used to catch the radio waves sent by the radio transmitter which are placed at various locations in a city. Using these transistors and receivers we can directly communicate with thousands of people they are used to communicate public information, broadcast news, and send emergency distress signals.

Radio Waves Uses

Radio waves are widely used for a variety of purposes. Radio waves have the highest wavelength among all electromagnetic waves and they can easily penetrate the atmosphere and structure materials, and can also twist around blocks by diffraction various uses of radio waves are

  • Radio Communication is the most common use of radio waves they are used for communicating to a wide range of audiences at once.
  • Cellular Networks use radio technology for establishing networks.
  • RADAR uses radio technology.
  • Satellite Communication has a wide use of radio technology
  • Navigation and Air Traffic Control also use radio technology.

Also, Check

Solved Examples on Radio Waves

Example 1: Calculate the speed of a radio wave having a wavelength of 280 m and a frequency of 1 MHz. 

Solution:

We have,

λ = 280

v = 1 × 106 

Using the formula we have,

vr = λv

    = 280 (106)

    = 2.8 × 107 m/s

Example 2: Calculate the speed of a radio wave having a wavelength of 35 m and a frequency of 2 MHz.

Solution:

We have,

λ = 35

v = 2 × 106

Using the formula we have,

vr = λv

    = 35 (2 × 106)

    = 7 × 107 m/s

Example 3: Calculate the speed of a radio wave having a wavelength of 150 m and a frequency of 1.5 kHz.

Solution:

We have,

λ = 150

v = 1.5 × 103

Using the formula we have,

vr = λv

    = 150 (1.5 × 103)

    = 2.25 × 105 m/s

Example 4: Calculate the wavelength of a radio wave having a speed of 3 × 106 m/s and a frequency of 1.5 MHz.

Solution:

We have,

vr = 3 × 106 

v = 1.5 × 106

Using the formula we have,

vr = λv

λ = (3 × 106)/(1.5 × 106)

   = 2 m

Example 5: Calculate the wavelength of a radio wave having a speed of 4 × 106 m/s and a frequency of 2 kHz.

Solution:

We have,

λ = 4 × 106

v = 2 × 103

Using the formula we have,

vr = λv

λ = (4 × 106)/(2 × 103)

   = 2000 m

Example 6: Calculate the frequency of a radio wave having a speed of 5 × 106 m/s and a wavelength of 500 m.

Solution:

We have,

vr = 5 × 106

λ = 500

Using the formula we have,

vr = λv

v = (5 × 106)/500

   = 10 kHz

Example 7: Calculate the frequency of a radio wave having a speed of 2.5 × 107 m/s and a wavelength of 800 m.

Solution:

We have,

vr = 2.5 × 107

λ = 800

Using the formula we have,

vr = λv

v = (2.5 × 107)/800

   = 31.2 kHz

FAQs on Radio Waves

Q1: What are radio waves?

Answer:

Radio waves are the waves in the electromagnetic spectrum with the highest wavelength. Their wavelength is in the range of 3kHz and 300 GHz. They are widely used for communication purposes.

Q2: Who discovered radio waves?

Answer:

The credit for discovering radio waves goes to Heinrich Hertz who discovered the existence of radio waves in the late 1880s. The complete radio transmission was achieved later by Italian scientist Guglielmo Marconi in the early 1900s.

Q3: How are radio waves produced?

Answer:

Fast-accelerating electrons or sub-atomic particles produce radio waves. They are generated by a radio transmitter and a radio receiver is used to collect these waves.

Q4: What are radio waves, give their two uses.

Answer:

Electromagnetic waves which have the highest wavelength in the electromagnetic spectrum are called radiowaves, they are widely used for the following purposes.

  • Radiowaves are widely used for communication purposes.
  • They are also used for operating machines remotely such as in Remote control toys.

Q5: Which sphere of Earth’s atmosphere radio waves are transmitted?

Answer:

The layer of Earth’s atmosphere which is used to transmit radio waves are Ionosphere.



Last Updated : 04 Feb, 2024
Like Article
Save Article
Previous
Next
Share your thoughts in the comments
Similar Reads