Question

Which electromagnetic waves are used in remote controllers (switches)?

Answer 1

Hint: The use of a remote controller is to operate an electronic device without the help of a cable or a wire. Hence, a remote controller helps in wireless communication. This communication works with help of one of the electromagnetic waves.

Complete step-by-step solution:
The main source of heat and energy for us is the sun. Sun emits waves called electromagnetic waves. These waves carry the heat and energy from the sun to the surface of the earth.
Electromagnetic waves consist of waves over a very wide range of wavelengths. Each electromagnetic wave from a certain range of wavelengths has particular features and uses.
The electromagnetic waves that are used in a remote controller are called radio waves. The radio waves have wavelengths ranging from 1 mm (i.e. shorter than a grain of rice) to 10,000 km (i.e. longer than the radius of our earth). Now, we can imagine how long the wavelength of a radio wave can be. These waves are invisible to a human eye.
The radio waves have contributed a lot to improvising communications. Due to the radio waves, we have wireless communications. For example, T.V’s, AC’s, and other electronic devices that work on a remote controller.
A remote controller consists of a transmitter. The transmitter emits a radio wave of a suitable wavelength, which is received and analyzed by the receiver present in the electronic device. In this way, the electronic device responds to a remote controller.

Note: Nowadays, the remote controllers use infrared waves also. As the radio waves, infrared waves are also invisible to a human eye. The infrared waves have shorter wavelengths compared to the wavelengths of the radio waves.