In satellite communication,the uplink frequency band used is

The process of superimposing a signal frequency (i.e.,audio wave) on a carrier wave is known as:

$A$ $TV$ transmission tower has a height of $140\, m$ and the height of the receiving antenna is $40\, m$. What is the maximum distance up to which signals can be broadcasted from this tower in $LOS$ (Line of Sight) mode? (Given: radius of earth $R = 6.4 \times 10^6\, m$)

If the highest modulating frequency of the wave is $5\, kHz$,the number of stations that can be accommodated in a $150\, kHz$ bandwidth are

Which of the following devices is not a transducer?

$A$ message signal of frequency $10 kHz$ and peak voltage of $15 V$ is used to modulate a carrier frequency of $1 MHz$ and peak voltage of $30 V$. Determine the modulation index.