Question

The remote control handset of T.V makes use of ________ of very low frequency.
A. microwaves
B. infrared radiations
C. visible rays
D. radio waves

Answer 1

Hint: All of the above given options belong to the electromagnetic spectrum. They vary from each other in terms of their use which depends on the frequency, and the wavelength radiation. Since we use TV remotes in houses on a daily basis, the radiation in the remote must be inert with the surroundings.

Complete step-by-step answer:
Let us discuss the property of each radiation for better understanding.
We know that microwaves are short wavelength and can produce heating effects. Used in microwaves to heat food.
Also, Radio waves are used to transmit information over long distances. And can ionise the air easily. Used in the transmission of TV and radio signals.
And visible rays can disturb our vision as they are visible to our eyes.
Hence microwaves, radio waves and visible rays are not used in the tv remotes.
Whereas, infrared rays are close to the visible region. But their wavelength is slightly longer than the visible region and is hence invisible to the naked eyes. These are generally used in short distance communications and LED lights.
Thus, Low frequency infrared radiations are used in the TV remote signals. As they are short distance invisible rays with low penetrating power , also they don't interact with the surrounding.

So, the correct answer is “Option B”.

Note: We know that the electromagnetic spectrum is a table which contains the information of the radiation, like its frequency, wavelength and its energy. However, all the radiations in the electromagnetic spectrum travel at the speed of light irrespective of their frequency and wavelength.