An amplitude modulated wave is represented by $V_{AM} = 10[1 + 0.4 \cos(2 \pi \times 10^4 t)] \cos(2 \pi \times 10^7 t) \text{ V}$. The total bandwidth of the amplitude modulated wave is:

$A$ carrier wave of peak voltage $10 \,V$ is used to transmit a message signal. What should be the peak voltage of the modulating signal in order to have a modulation index of $80 \%$ (in $\,V$)?

If a $TV$ transmission is broadcast from a $TV$ transmitter tower of height $h$,then the maximum distance of this transmission is proportional to the height $h$ of the tower as.........

In satellite communication,the uplink frequency band used is

The transmitting antenna placed at the top of a tower has a height of $45 \ m$ from the ground. The distance between receiving and transmitting antennas is $40 \ km$ and the radius of earth is $6400 \ km$. The minimum height (in $m$) at which the receiving antenna is to be placed for satisfactory communication in $LOS$ mode,is

$A$ bandwidth of $6 \, \text{MHz}$ is available for $A.M.$ transmission. If the maximum audio signal frequency used for modulating the carrier wave is not to exceed $6 \, \text{kHz}$,the number of stations that can be broadcasted within this band simultaneously without interfering with each other will be ..... .