All Exams Test series for 1 year @ ₹349 only
Question

Arrange the following EM waves in increasing order of their frequency?

A. Ultraviolet rays

B. Gamma rays

C. Radio waves

D. Infrared waves

E. X-rays

Choose the correct answer from the options given below: 

The correct answer is

C < D < A < E < B

Let's understand the arrangement of electromagnetic (EM) waves based on their frequency. The electromagnetic spectrum is the range of all types of electromagnetic radiation, which are forms of energy that travel and spread out as they go – the visible light that comes from a lamp in your house and the radio waves that come from a radio station are two types of electromagnetic radiation.

Understanding Electromagnetic Waves and Frequency

Electromagnetic waves are disturbances that propagate through space or through a medium at the speed of light. They consist of oscillating electric and magnetic fields that are perpendicular to each other and to the direction of propagation.

Frequency is a measure of how many wave cycles pass a point in one second. It is typically measured in Hertz (Hz).

The different types of electromagnetic waves are ordered in the electromagnetic spectrum according to their frequency and wavelength. Frequency ($\nu$) and wavelength ($\lambda$) are inversely related, meaning as frequency increases, wavelength decreases, and vice versa. This relationship is given by the formula:

$\nu = \frac{c}{\lambda}$

where $c$ is the speed of light in a vacuum.

Ordering EM Waves by Increasing Frequency

The standard order of electromagnetic waves from lowest frequency (longest wavelength) to highest frequency (shortest wavelength) is:

  1. Radio waves
  2. Microwaves
  3. Infrared radiation
  4. Visible light
  5. Ultraviolet radiation
  6. X-rays
  7. Gamma rays

The question asks to arrange the given EM waves (Ultraviolet rays, Gamma rays, Radio waves, Infrared waves, X-rays) in increasing order of their frequency. Let's map the given options to the standard spectrum order:

  • Radio waves (C): Lowest frequency among the given options.
  • Infrared waves (D): Higher frequency than radio waves, but lower than visible light.
  • Ultraviolet rays (A): Higher frequency than visible light and infrared, but lower than X-rays.
  • X-rays (E): Higher frequency than ultraviolet, but lower than gamma rays.
  • Gamma rays (B): Highest frequency among the given options.

Therefore, the increasing order of frequency for the given waves is:

Radio waves < Infrared waves < Ultraviolet rays < X-rays < Gamma rays

In terms of the labels (A, B, C, D, E):

C < D < A < E < B

Summary of EM Wave Order

EM Wave Type Relative Frequency Relative Wavelength
Radio waves Lowest Longest
Microwaves
Infrared
Visible Light
Ultraviolet
X-rays
Gamma rays Highest Shortest

Comparing the derived order C < D < A < E < B with the provided options, we find the matching sequence.

Conclusion

Based on the electromagnetic spectrum, the order of the given waves from lowest to highest frequency is Radio waves (C), followed by Infrared waves (D), then Ultraviolet rays (A), followed by X-rays (E), and finally Gamma rays (B).

Revision Table: EM Spectrum Order

EM Wave Symbol Approximate Frequency Range (Hz) Order by Increasing Frequency
Radio waves C < 3 $\times 10^9$ 1 (Lowest)
Infrared waves D $3 \times 10^{11}$ to $4 \times 10^{14}$ 2
Ultraviolet rays A $8 \times 10^{14}$ to $3 \times 10^{16}$ 3
X-rays E $3 \times 10^{16}$ to $3 \times 10^{19}$ 4
Gamma rays B > $3 \times 10^{19}$ 5 (Highest)

Note: The frequency ranges are approximate and can vary slightly depending on the source.

Additional Information on Electromagnetic Waves

Each type of electromagnetic wave has unique properties and applications:

  • Radio waves: Used for communication (radio, television, mobile phones). They have the longest wavelengths and lowest frequencies.
  • Infrared waves: Associated with heat. Used in remote controls, thermal imaging, and night vision goggles.
  • Ultraviolet rays: Emitted by the sun. Can cause sunburn and are used in sterilization and fluorescent lamps.
  • X-rays: High energy waves used in medical imaging (like X-rays) and security scanners. They can penetrate soft tissues.
  • Gamma rays: The highest energy waves, produced by radioactive decay and nuclear reactions. Used in cancer treatment (radiotherapy) and sterilization.

Understanding the order of these waves in the electromagnetic spectrum is fundamental in physics and has numerous practical applications.

Was this answer helpful?

Important Questions from Electromagnetic Waves

  1. In an electromagnetic wave, the ratio of energy densities of electric and magnetic fields is:

  2. What will be the time taken by light to travel 2cm thickness of glass of refractive index 1.5?

  3. Calculate the ratio of the range of a transmitting antenna of height 64 m to the receiving antenna of height 16 m:

  4. A plane electromagnetic wave of frequency 30 MHz travels in free space along the x-direction. At a particular point in space and time, \(\vec{E}\)=6.3j^​V/m. The \(\vec{B}\) at this point would be:

  5. Match List - I with List - II

    List-IList-II
    (A) Microwave(I) Radar System for Aircraft Navigation
    (B) UV Rays(II) To study crystal structure
    (C) X-Rays(III) Radioactive decay of Nucleus
    (D) Gamma-Rays(IV) Lasik eye surgery

    Choose the correct answer from the options given below:

Need Expert Advice?

Start Your Preparation with Prepp Mobile App

Download the app from Google Play & App Store
Download the app from Google Play & App Store
Prepp Mobile App