For the propagation of $10 \ MHz$ signals as sky waves,what should be the minimum electron density in the ionosphere?

In a line of sight radio communication,a distance of about $50\, km$ is kept between the transmitting and receiving antennas. If the height of the receiving antenna is $70\, m$,then the minimum height of the transmitting antenna should be........$m$ (Radius of the Earth $= 6.4 \times 10^6\, m$)

The total power in an $AM$ wave is $1500 \ W$. What is the power transmitted by the carrier for $100\%$ modulation (in $W$)?

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 $= 6.4 \times 10^6 \ m$) (in $m$)

Match the following:

List-$I$ (Signal)	List-$II$ (Bandwidth)
$i$. Speech Signal	$a$. $4.2 \text{ MHz}$
$ii$. Music Signal	$b$. $6 \text{ MHz}$
$iii$. Video Signal	$c$. $20 \text{ kHz}$
$iv$. $T$.$V$. Signal	$d$. $2.8 \text{ kHz}$

An amplitude modulated signal consists of a message signal of frequency $1 \text{ kHz}$ and peak voltage of $5 \text{ V}$,modulating a carrier frequency of $1 \text{ MHz}$ and peak voltage of $15 \text{ V}$. The correct description of this signal is