Question

Electromagnetic radiation with maximum wavelength is:
(A) Ultraviolet
(B) Radiowave
(C) X-ray
(D) Infrared

Answer 1

Hint: It is the electromagnetic radiation which is used in communication technologies such as mobile phones, Wi-Fi, television, radio and so on. Heinrich Hertz discovered this type of waves. It is used to separate electrons from atoms and molecules, chemical changes in DNA and even in cooking food at home.

Complete step by step answer:
- Clark Maxwell first told that the radio waves existed. Heinrich Hertz demonstrated this wave in the lab.
- Like other electromagnetic radiations, they also travel at the speed of the light in the vacuum.
- They are formed by the electric charges under acceleration. These electric charges flow in a special metal conductor called antenna, then transmitted through a transmitter and finally received by the radio receiver. Radio waves occurring naturally are by lightning and astronomical objects.
- Electromagnetic radiation with maximum wavelength is the radio wave.
- The frequency ranges between 300 gigahertz (GHz) to 30 hertz (Hz).
- The representation of various types of electromagnetic radiation and its relation with energy and wavelength is shown in the following figure.

- Thus, from the figure, we can say that Radio waves will have least energy and will have the highest wavelength amongst them all.
-Nowadays, it is used as broadcasting radar, communication satellite, computer network, wireless devices such as earphones, computers and so on.
-Wi-Fi uses radio waves through wireless internet routers popularly known as LAN. It uses frequencies between 2.4 to 5.8 GHz.

So, the correct option is (B) Radiowave.

Note:
The wavelength of a wave is inversely proportional to the energy of the wave. Thus, we can say that as the wavelength of a wave increases, its energy decreases and as its wavelength decreases, its energy increases.