Question

Which one of the following rays has minimum frequency?
(A) Ultraviolet rays
(B) X-rays
(C) \[\gamma \] rays
(D) Infrared rays

Answer 1

Hint: In the given question, we have been given several forms of electromagnetic radiations and we have been asked to choose the radiations having minimum frequency. To find the correct answer to the given question, we need to have a basic knowledge of the electromagnetic spectrum. Let’s head over to the discussion in the step by step solution section.

Complete step by step solution:
Electromagnetic radiation refers to waves of electromagnetic nature that travel through space and radiate energy. When all the forms of electromagnetic radiation are ranged according to their frequency or wavelength, the resulting table is termed as an electromagnetic spectrum. Since it is a known fact that the energy carried by a wave is directly proportional to its frequency, we can say that the electromagnetic radiation having higher frequency will carry higher energy.
When the electromagnetic radiations are ranged based on their frequency, it is observed that radio waves come at the last of the list because of their extremely small frequency. The radio waves are preceded by microwaves and infrared waves. Then comes the visible part of our spectrum, which helps us to perceive objects around us. Having comparatively higher frequency, ultraviolet rays come next in the list, preceded by X-rays and finally, at the top of the list we have gamma rays with highest frequency among all electromagnetic radiations.
Hence, we can say that among the options listed in the question, infrared radiations have the smallest frequency.

hence option (D) is the correct answer to the given question.

Note:
Students often have a doubt regarding the application of the electromagnetic spectrum and the sorting of the types of electromagnetic radiations. The electromagnetic spectrum helps scientists in studying the specific properties and also the variations in the properties of the radiations which eventually helps them to put different electromagnetic radiations to their appropriate usage.