$A$ carrier is simultaneously modulated by two sine waves with modulation indices of $0.4$ and $0.3$. The resultant modulation index will be

The antenna current of an $AM$ transmitter is $8 \ A$ when only the carrier is sent,but it increases to $8.96 \ A$ when the carrier is modulated by a sine wave. The percentage of modulation is: (in $\%$)

The amplitude of the side bands of the modulated signal, if the carrier signal and message signal amplitudes are $25 \,V$ and $5 \,V$ respectively, is (in $\,V$)

$12$ signals,each band-limited to $5\, kHz$,are to be transmitted by frequency-division multiplexing. If an $AM-SSB$ modulation guard band of $1\, kHz$ is used,then the bandwidth of the multiplexed signal is ....... $kHz$.

For an amplitude modulated wave the minimum amplitude is $3\,V$,while the modulation index is $60\%$. The maximum amplitude of the modulated wave is $......\,V$ (in $,V$)

In amplitude modulation,the message signal $V_{m}(t) = 10 \sin(2 \pi \times 10^{5} t) \text{ V}$ and the carrier signal $V_{c}(t) = 20 \sin(2 \pi \times 10^{7} t) \text{ V}$. The modulated signal contains the message signal with lower sideband and upper sideband frequencies. Therefore,the bandwidth of the modulated signal is $\alpha \text{ kHz}$. The value of $\alpha$ is: