How can waves be used for communication

Also, when radio waves are absorbed by a conductor , they create an alternating current. This electrical current has the same frequency as the radio waves. Information is coded into the wave before transmission, which can then be decoded when the wave is received. Television and radio systems use this principle to broadcast information.

Microwaves are used for cooking food and for satellite communications. High frequency microwaves have frequencies which are easily absorbed by molecules in food. The internal energy of the molecules increases when they absorb microwaves, which causes heating. Microwaves pass easily through the atmosphere, so they can pass between stations on Earth and satellites in orbit. One of the best-known examples of wireless technology is the mobile or cellular phone, with more than 4. These wireless devices use radio waves to enable their users to make phone calls from many locations worldwide.

They can be used within range of the mobile telephone sites that house the necessary equipment to transmit and receive the radio signals these devices emit. Wireless data communications are also an essential component of mobile computing.

The various available technologies differ in local availability, coverage range, and performance. In some circumstances, users must be able to employ multiple connection types and switch between them.

To simplify the experience for the user, connection manager software is available, or a mobile VPN can be utilized to handle the multiple connections as a secure, single virtual network. One popular supporting technology is Wi-Fi, a wireless local area network that enables portable computing devices to connect easily to the Internet. Standardized as IEEE Wi-Fi has become the de facto standard for access in private homes, within offices, and at public hotspots.

Some businesses charge customers a monthly fee for the service, while others offer it for free in an effort to increase sales of their goods.

The shorter the wavelength of an EM wave, the higher its frequency. In this approach, rather than creating a wave with one constant wavelength and one constant frequency, a wave is produced where the wavelength, the distance from one crest to another, varies. And along with this, the frequency of the wave changes too. FM stands for frequency modulation, changing the frequency of a wave within the wave in order to package more information in the signal. The frequency of radio waves is being modulated, changed, so the waves carry more information.

Which of the following types of electromagnetic waves is not used for sending communication signals? Infrared waves, microwaves, visible-light waves, ultraviolet waves, radio waves. Okay, so here we want to identify which of these five options is not used for sending communication signals.

Now theoretically, any type of wave could be useful in some application for communicating. We can start at the top of the list and go down, thinking in each case how that particular kind of wave is used or not used in communication.

Starting off with infrared waves, this kind of wave is not typically used to communicate over long distances. But it has been found to be useful for communicating wirelessly over short distances. Think, for example, of any remote controls we might use. We might be sending a signal to power on a monitor, turn off a television, or open our garage door. We might first associate these kinds of waves with a microwave oven, something to heat food.

These waves are unlikely to be blocked or reflected back. Unlike microwaves, visible light is not useful for long-distance communication through the open atmosphere. But with the right constraint, visible light can be useful for sending communication signals.

One way this happens is through what is called an optical fiber. An optical fiber is a long wire that has a glass core, a glass interior to it. This interior is covered in a coating. And the way it works is, light is accepted through one end of the fiber and then, regardless of the twists and turns the fiber might go through, that light is safely communicated out the other end.

This communication distance from one end of the fiber to the other can be on the order of centimeters or thousands of kilometers. This means that visible-light signals are useful for communication. Next up is ultraviolet waves. And not only do they have trouble traveling through the atmosphere, but these waves are also invisible to the human eye.

Along with all this, ultraviolet waves are high-energy enough so that some of them are dangerous to humans. They can negatively affect the DNA in our cells and therefore are often avoided. It looks like ultraviolet waves will be the wave type that are not used for sending communication signals. In this case, we can easily think of applications of radio waves for communication. So then we can finalize our choice of ultraviolet waves as the type of electromagnetic waves that are not used for sending communication signals.