Advertisements
Advertisements
प्रश्न
Describe briefly, by drawing suitable diagram, the sky wave ?
उत्तर
In the frequency range from a few MHz up to 30-40 MHz, long distance communication can be achieved by ionospheric reflection of radio waves back towards the earth. This mode of propagation is called sky wave propagation. The ionosphere consists of large number of ions or charged particles due to ionisation in the presence of ultraviolet rays. The degree of ionisation varies with height. At a certain height, there occurs a peak of ionisation density which acts as a reflector of certain range of frequencies. This phenomenon is shown in the figure below:
APPEARS IN
संबंधित प्रश्न
What is space wave propagation?
Four nuclei of an element undergo fusion to form a heavier nucleus, with release of energy. Which of the two – the parent or the daughter nucleus – would have higher binding energy per nucleon?
An em wave is travelling in a medium with a velocity `vecv =vhati` Draw a sketch showing the propagation of the em wave, indicating the direction of the oscillating electric and magnetic fields.
Name the three different modes of propagation of electromagnetic waves. Explain, using a proper diagram the mode of propagation used in the frequency range from a few MHz to 40 MHz.
Explain with the help of a diagram how long distance communication can be achieved by ionospheric reflection of radio waves.
In sky wave mode of propagation, why is the frequency range of transmitting signals restricted to less than 30 MHz?
Answer the following question.
On what factors does the range of coverage in ground wave propagation depend?
What do you mean by skip distance?
The wavelength of electromagnetic wave employed in space communication very over a range of
The radio wave of frequency 300 MHz to 3000 MHz be.long to
