Write down Properties of radio waves?

Question

Digital Communication system

Answer 1

Radio waves are



1. Transverse electro magnetic waves.

2 Frequency is from a few hertz to giga hertz.

3 Low frequency waves are reflected and also absorbed by the ionosphere.



4. Upto mega hertz frequencies are used in the radio wave communications/



5 Higher frequencies above tens of mega hertz are used in satellite communications



6 These waves can be linearly polarized, circularly polarized and elliptically polarized/.

Answer 2

Characteristics of Radio Waves

1. Radio Wave's Directness



As a frequency gets higher, the wave length gets shorter, and the directness and refractiveness increase, It approaches the properties of light.



Also, if there is an obstacle that is hard for the radio wave to pass through, on the other side of this obstacle, the radio wave becomes weak, it refracts and multi-path noise (feedback) occurs.



* Basically, when a wave length is long, the cordless phone's antenna should be long. However, when a wave length is short, the antenna should be also be short, This is why the length of antenna of the 900 MHz cordless phone is shorter than 43/49Mhz cordless phone.

2. Noise Occurrence



When a radio wave is weak, (when the electric signal is small), noise increases. For example, the further the distance between the base unit and the portable unit (inverse proportion to distance squared), the radio wave will become weaker And, at a certain level, the noise (radio wave disturbance). There is also the possibility that the cordless phone may receive interference when operated near a radio or TV station, electric cable, etc.

Answer 3

Radio waves are those waves that are transmitted and reflected under the ionosphere only. It is used in transmitting and reflecting the signals from radio, transistors, tvs, etc. These electromagnetic waves are of frequency range 5x10^5 to 10^9 Hz. It is used in amplitude modulated band, short wave bands and ultra high frequency bands also.

Answer 4

mild does not now not have inertia, inertia applies to our bodies, mild isn't a physique, does not have our bodies, and it isn't composed of our bodies. mild does not decelerate by way of the years, it isn't plagued by employing time or distance and the value of sunshine is a cosmological consistent mild won't be able to be sucked right into a black hollow, in spite of the certainty that technically it particularly is precise to declare that mild won't be able to get away from a black hollow... the get away velocity required is larger the the value of sunshine gravity can divert or bend mild, it does not sluggish it down.Magnetic fields have not have been given any consequence on it in any admire... mild, now not being composed of iron, isn't concern to magnetism you ideals concerning the habit of sunshine while hitting water and good be counted at the instant are not supported by employing experimental consequences, a number of which immediately refute your factors. You point out the electromagnetic spectrum, of which mild is in straightforward terms a small area, yet you fail to handle how the Photon, an imperative area of the seen spectrum is uniquely or specially affected.... why do seen observations, radio telescopes and x-ray spectrometers practice comparable places for comparable gadgets? if mild bogged down and radios waves did now not, there could be a distinction... if all 3 are slowed, how do you clarify equivalent and comparable expenditures of slowing for "gadgets" which would be stopped by employing an opaque piece of paper (mild) and rays that could penetrate something as much as the density of lead (xrays)