Electromagnetic waves with wavelength
(i) ${\lambda _1}$ is used in satellite communication
(ii) ${\lambda _2}$ is used to killed germs in water purifier,
(iii) ${\lambda _3}$ is used to detect leakage of oil in underground pipelines
(iv) ${\lambda _4}$ is used to improve visibility in runways during fog and mist conditions.
1) Identify and name the part of the electromagnetic spectrum to which these radiations belong.
2) Arrange these wavelengths in ascending order of their magnitude
3) Write one more application of each.

Hint: In satellite communications, microwaves and radio waves are used. In water purifiers UV rays are used. X-rays are used to detect oil leakages. Infrared rays are used to improve visibility on runways during fog and mist conditions. Arrange them according to their wavelengths.

Complete answer:
Let’s discuss some functions of rays:
$1)$ Gamma-rays: They are used to get information on the nuclear structure and medical treatments.
X-rays: They are used in medical diagnosis and treatment study of crystal structure. They are also used for industrial radiography.
Visible light: We know, it helps us to see objects.
Microwave and Radio waves: They are used in radio and telecommunication.

$2)$ The ascending order of their wavelengths is:
Gamma rays < X-rays < UV rays < Visible light < Infrared rays < Radio waves

$3)$ Applications of each of them:
Radio waves: Radio waves are absorbed by conductors and in return they create an alternating current. Televisions and radio systems signals are coded.
Microwaves: They are also used for cooking food.
Infrared: Used in electric heaters, cookers, cameras. The human eye is not capable of seeing this light.
Visible light: Also used in fibers optics communications.
UV rays: Ultraviolet rays are also good for skin as it helps to make vitamin D. However, too much exposure may also lead to skin problems.

Note: Visible light is also used in fibers optic communication. Microwaves apart from radio waves are also used in radio communication and telecommunication. Wavelength and energy are inversely proportional, waves having lower wavelengths have more energy thus, they are dangerous.