In $AM$,the cent percent modulation is achieved when

If the highest frequency modulating a carrier is $5\, kHz$,then the number of $AM$ broadcast stations accommodated in a $90\, kHz$ bandwidth are ....... .

$A$ message signal of frequency $5\,kHz$ is used to modulate a carrier signal of frequency $2\,MHz$. The bandwidth for amplitude modulation is $..........\,kHz$.

The $T.V.$ transmission tower in Delhi has a height of $245 \ m$. The distance up to which the broadcast can be received (taking the radius of the earth to be $6.4 \times 10^6 \ m$) is .......... $km$.

In an amplitude modulation,a modulating signal having amplitude of $X$ Volt is superimposed with a carrier signal of amplitude $Y$ Volt in the first case. In the second case,the same modulating signal is superimposed with a different carrier signal of amplitude $2Y$ Volt. The ratio of the modulation index in the two cases respectively will be:

In amplitude modulation,the sinusoidal carrier frequency is denoted by $\omega_c$ and the signal frequency is denoted by $\omega_m$. The bandwidth of the signal is such that $\omega_m << \omega_c$. Which of the following frequencies is not contained in the modulated wave?