Communication Systems · Physics · AP EAPCET

The heights of tansmitting and receiving antennas are respectively $\frac{1}{20000}$ and $\frac{1}{80000}$ times the radius of the

Earth. The maximum distance between these two antennas for satisfactory communication in line of sight mode is

(Radius of the Earth $=6.4 \times 10^6 \mathrm{~m}$ )

In amplitude modulation, if a message signal of 5 kHz 2 is modulated by a carrier wave of frequency 900 kHz , then the frequencies of the side bands are

If the ratio of the maximum and minimum amplitudes of an amplitude modulated wave is $7: 3$, then the modulation index is

Ionosphere acts as a reflector for the frequency range of

For transmitting a signal of frequency 1000 kHz , the minimum length of the antenna is

If in an amplitude modulated wave, the maximum amplitude is 14 V and the modulation index is 0.4 , then the amplitude of the carrier wave is

In amplitude modulation of waves, the maximum amplitude is 30 mV and minimum amplitude is 5 mV , then the modulation index is

If the sum of heights of transmitting and receiving antennas in line of sight of communication is ' $h$ ' then the height of receiving antenna, to have the range maximum is

The maximum distance between the transmitting and receiving antennas for satisfactory communication in line of sight mode is 57.6 km . If the height of the receiving antenna is 80 m , the height of the transmitting antenna is (radius of earth $=6.4 \times 10^6 \mathrm{~m}$ )