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Electromagnetic waves - radio waves - propagate through the air and vacuum by altering the electro-magnetic (EM) properties of space. They will be reflected whenever the EM properties of the space change. Incoming radiation from the sun partly ionizes some of the air molecules in the upper atmosphere and, for some frequencies, this will reflect (or refract) the EM signal.
This allows the EM signal to be reflected over long distances - even around the world - multiple hops. This effect is only true for HF radio - frequencies up to 10MHz or so. And varies naturally, day and night.
A related phenomenon affecting the upper atmosphere, is that incoming meteorites may give temporary ionization tracks. These have been used for burst transmissions but are not suitable for broadcast communications.
Higher frequencies, 100 MHz or so, use line - of - sight transmission, for these high frequencies are not affected by the ionized layers.
Sky propagation involves radio waves reflecting off the Earth's ionosphere to reach a receiver beyond the horizon, whereas line-of-sight propagation involves radio waves traveling in a straight path from the transmitter to the receiver without any obstacles in between. Sky propagation is typically used for long-distance communications, while line-of-sight propagation is more commonly used for shorter distances.
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Is it sexist to have dress codes differ by gender?
This is a matter of opinion rather than law. My opinion is that: As items of clothing differ by gender it is not sexist for dress codes to differ by gender.
How do theories differ?
Theories differ in their level of explanation and scope. Some theories focus on explaining specific phenomena in detail, while others offer broader explanations that encompass multiple related phenomena. Additionally, theories can also differ in terms of their underlying assumptions and the evidence that supports them.
How do you the concept of grass letters root letters and sky letters to the child?
You can explain to the child that grass letters are lowercase letters that start on the baseline, root letters are lowercase letters that go below the baseline, and sky letters are lowercase letters that go above the baseline. You can use visual aids or examples to help them understand the concept better.
How do the educational policies differ?
Educational policies can differ in terms of funding allocation, curriculum design, assessment methods, and teacher training requirements. Additionally, policies may vary in their emphasis on standardized testing, inclusion of special needs students, bilingual education, and technology integration. These differences can impact the overall quality and equity of education within a given system.
When a teachers voice carries out the classroom through an open door and is heard down the hall what type of interaction is most likely the cause?
One likely cause is sound wave propagation. When a teacher speaks loudly, sound waves travel through the air and can easily pass through the open door and down the hall, allowing the voice to be heard.
How does natural vegetative propagation differ from artificial vegetative propagation?
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What is the different modes of the radio wave propagation?
Ground wave, sky wave and space wave propagation
What are the applications of sky wave propagation?
Sky wave propagation is used in long-distance radio communications. It is commonly used for broadcasting, military communications, and amateur radio operations. Sky wave propagation allows signals to be transmitted over long distances without the need for expensive infrastructure.
What is in the sky starting with a c can differ in sizeshape and color?
Clouds
How is termination differ from propagation step?
Termination is the final step in a reaction where the reactive species are consumed to produce stable products, effectively stopping the reaction. In contrast, propagation steps are where reactive species are generated and utilized to carry out the main chemical transformations in a reaction, allowing it to proceed. Termination ends the reaction, while propagation keeps it going.
How do available stars differ from other stars in the sky?
The available ones are above the horizon in a dark sky. The other ones are unavailable.
How does the motion of the medium differ between transverse and longitudinal waves?
In transverse waves, the particle motion is perpendicular to the direction of wave propagation, creating crests and troughs. In longitudinal waves, the particle motion is parallel to the direction of wave propagation, causing compressions and rarefactions in the medium.
Definition of guided unguided media?
The unguided media is the wireless media. It simply transports electromagnetic waves without using any physical conductor. Signals are normally broadcast through the air and thus are available to any one who has the device capable of receiving them. Unguided signals can be travelled from source to the destination in several ways. These ways include ground propagation, sky propagation and line of sight propagation.
How are all electromagnetic waves alike how ado they differ?
All electromagnetic waves are forms of energy that travel through space at the speed of light, carrying energy without needing a medium for propagation. They differ in their wavelengths and frequencies, which determine their properties such as their interaction with matter and their applications in technology.
When was Propagation - album - created?
Propagation - album - was created in 1994.
What type of propagation is used in telephone communication?
Wave propagation
What does the term artificial propagation mean?
Propagation carried out by man and not naturally.
