For transmitting a signal of frequency $1000 \text{ kHz}$, the minimum length of the antenna is (in $\text{ m}$)

Long range radio transmission is possible when the radio waves are reflected from the ionosphere. For this to happen,the frequency of the radio waves must be in the range:

$A$ 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 $\,V$)?

The maximum distance up to which $TV$ transmission from a $TV$ tower of height $h$ can be received is proportional to

$A$ $TV$ transmission antenna at a particular station has a height of $100 \, m$. By how much should the height of the antenna be increased to double its coverage range (in $m$)?

$A$ carrier wave of peak voltage $14\,V$ is used for transmitting a message signal. The peak voltage of the modulating signal required to achieve a modulation index of $80\%$ will be.......$V$