Question

Out of X-rays, visible, ultraviolet, radio-waves, the largest frequency is of:
(A) X-rays
(B) Visible
(C) Ultraviolet
(D) Radio Waves

Answer 1

To solve this question, we must first understand some basic concepts about frequency. Then we need to assess concepts in such a way that we may easily predict the order of frequencies of the given waves and then only we can conclude the correct answer.

Complete step-by-step answer: Before we move forward with the solution of this given question, let us first understand some basic concepts:
Frequency: is defined as a total number of vibrations or oscillations present in a wave in a unit time. The fundamental unit of measuring the frequency is Hertz, shortly written as $Hz$. Suppose a sound wave is producing total $5$ complete vibrations in a second. Then it is said that the frequency of the wave is $5\,\,Hz$. Thus we can say, $1\,Hz$ of frequency specifies $1$ complete vibration or oscillation per second.
The minimum distance between the two consecutive identical wave points is known as wavelength. Radio waves, television waves, and microwaves are all types of electromagnetic waves. They only differ from each other in wavelength. Wavelength is the distance between one wave crest to the next.
Relation between wavelength and frequency: $frequency\, = \,\,\dfrac{{speed}}{{wavelength}}$
So from the above formula we can conclude that to have the largest frequency, wavelength must be lowest.And among X-rays, visible, ultraviolet, radio-waves, the lowest wavelength is of X-rays and therefore the largest frequency is of X-rays.

So, clearly we can conclude that the correct answer is Option (A).

Note: X-rays are a form of electromagnetic radiation, similar to visible light. Unlike light, however, x-rays have higher energy and can pass through most objects, including the body. Medical x-rays are used to generate images of tissues and structures inside the body.