Question

If, ${V_g}$, $\,{V_{x\,}}\,$ and ${V_m}$ are speeds of gamma rays, X rays , and microwaves respectively in vacuum, then:
A. ${V_g}\, < \,{V_{x\,}}\, < {V_m}$
B. ${V_{g\,}}\, > {V_x} > \,{V_m}$
C. ${V_g}\, < \,{V_x}\, > {V_m}$
D. ${V_g}\, = {V_x} = \,{V_m}$

Answer 1

Hint: Electromagnetic waves are the waves created as a result of vibrations of the electric and magnetic fields. These waves are composed of oscillating electric field and magnetic field which are perpendicular to each other and perpendicular to the direction of propagation of the wave.
Various forms of electromagnetic radiations are as follows.
Gamma-ray, x-ray, ultraviolet, visible, infrared, microwave, and radio wave.
The peculiarity of electromagnetic radiations is that the speed of all electromagnetic waves is a constant in a vacuum. The Value of this constant is $c = 3 \times {10^8}m/s$

Complete step by step answer:
Electromagnetic waves are the waves created as a result of vibrations of the electric and magnetic fields. These waves are composed of oscillating electric fields and magnetic fields which are perpendicular to each other and perpendicular to the direction of propagation of the wave.
Electromagnetic radiation is a form of energy which takes many forms such as radio waves, microwave, x-ray, gamma-ray, etc.
In the increasing order of wavelengths, electromagnetic radiations can be arranged as:
Gamma-ray, x-ray, ultraviolet, visible, infrared, microwave, and radio wave
The peculiarity of electromagnetic radiations is that the speed of all electromagnetic waves is a constant in a vacuum. The Value of this constant is $c = 3 \times {10^8}m/s$
So, the speed of gamma-ray, x-Ray, and microwave which are part of electromagnetic radiation will be the same.

${V_g}\, = {V_x} = \,{V_m}$. Hence the answer is option D.

Note:
Only the speed of all electromagnetic radiations in a vacuum is constant. But other parameters such as frequency and wavelength of this radiation differ.