The minimum size of an antenna for transmitting electromagnetic waves at $1500 \text{ MHz}$ is

Which characteristic of a carrier light wave is modulated for the modulation of a light wave?

Which device is used to convert one form of energy into another?

For effective transmission of a wave with frequency $3000 \text{ kHz}$,the minimum length of the antenna should be ...... $m$.

$A$ carrier signal $C(t)=25 \sin(2.512 \times 10^{10} t)$ is amplitude modulated by a message signal $m(t)=5 \sin(1.57 \times 10^{8} t)$ and transmitted through an antenna. What will be the bandwidth of the modulated signal?

The radio horizon of the transmission of an antenna placed on the $20^{\text{th}}$ floor in a shopping mall,where the height of each floor is $2 \,m$,is (Radius of Earth is $6.4 \times 10^6 \,m$): (in $\,km$)