Wave Motion (Physics)

Infrared rays are commonly used in TV remote control. Remote control can be used to operate devices such as television set, DVD player or other home appliances.

Infrared rays are commonly used in TV remote control. Remote control can be used to operate devices such as television set, DVD player or other home appliances.

Infrared rays are commonly used in TV remote control. Remote control can be used to operate devices such as television set, DVD player or other home appliances.

Infrared waves are used to transmit radio and TV signals but some of them are using radio waves. Infrared is an electromagnetic radiation.

The microwaves are high-frequency signals in the 300 MHz to 300 GHz range. The signals can carry thousands of channels at the same time, making it a very versatile communication system.

Microwave is often used for point to-point telecommunications. Today microwave is employed by telecommunication industry in the form of both terrestrial relays and satellite communication.

The process of superimposing any information (audio or video messages) on carrier radiowaves is called modulation.

Edwin Howard Armstrong was an American electrical engineer who invented wideband frequency modulation (FM) radio. Armstrong presented his paper, "A Method of Reducing Disturbances in Radio Signaling by a System of Frequency Modulation", (which first described FM radio) before the New York section of the Institute of Radio Engineers on November 6, 1935.

The paper was published in 1936. FM requires a wider signal bandwidth (and higher frequency range) than amplitude modulation (AM) by an equivalent modulating signal; this also makes the signal more robust against noise and interference.

In frequency modulation, the carrier amplitude and phase remains constant, but its frequency changes in accordance with the modulating signal.

FM broadcasting service uses the range of frequency bands between 88 to 108 MHz. There is a number of band allocation used around the globe:

1. 87.5-108 MHz - It is the "standard" VHF FM band. The one which is most widely used around the globe.

2. 76-90 MHz - This VHF FM band is used in Japan.

3. 65.8-74.0 MHz- This VHF FM band is known as the OIRT band. It was used in Eastern Europe although few other countries such as Russia, Ukraine also use it.

Both the statements are incorrect in the context of the question. Radio waves have a very long wavelength but the presence of electrically charged ions in ionosphere facilitate radio communication.