Question

If we denote microwaves, X rays, infrared, gamma rays, ultra-violet, radio waves, and visible parts of the electromagnetic spectrum by M, X, I, G, U, R, and V, the following is the arrangement in ascending order of wavelength:
A) R,M,I,V,U,X and G
B) M,R,V,X,U,G and I
C) G,X,U,V,I,M and R
D) I,M,R,U,V,X and G

Answer 1

Hint
Electromagnetic waves can have varying wavelengths and frequencies. Gamma rays have the lowest wavelength and long radio waves have the highest wavelength.

Complete step by step answer
The electromagnetic (EM) spectrum is the range of all types of EM radiation.
Radio waves have the longest wavelength in the spectrum. They are utilized by radio stations, satellites to send signals over long distances.
Microwaves come after radio waves in the spectrum in terms of wavelength. Microwaves are used to cook food and they’re used by astronomers to study galaxies.
Then we have the infrared waves which are the waves emitted by room temperature objects. Night vision goggles track the infrared right coming from an object to track it.
The visible parts of the electromagnetic spectrum include all the wavelengths that we can see with our eyes which is why it is called the visible part of the spectrum.
Then we have ultraviolet waves that are more energetic than visible waves and can damage human skin. It is usually emitted by very hot objects such as the Sun.
X-rays are the next on the list. They have lower wavelengths and enough penetrating power to cross our muscles but will interact with bones due to their higher density. X-rays are used to study bone injuries in humans.
The gamma rays have the smallest wavelength and hence the highest energy of all parts of the electromagnetic spectrum.
Hence the correct choice is option (A).

Note
To answer such problems we must remember the order of different parts of the electromagnetic spectrum. If instead of the order of the spectrum in terms of its wavelength, we remember the spectrum in terms of frequency, we can simply reverse the order so the frequency of an EM wave is inversely proportional to its wavelength.