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 $\%$)

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:

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

An amplitude modulated wave is modulated to $50\%$. If the carrier and one of the sidebands are suppressed,the percentage reduction in power is ....$\%$

$A$ modulating signal $2 \sin (6.28 \times 10^{6} t)$ is added to the carrier signal $4 \sin (12.56 \times 10^{9} t)$ for amplitude modulation. The combined signal is passed through a non-linear square law device. The output is then passed through a band pass filter. The bandwidth of the output signal of the band pass filter will be $MHz$.

$A$ carrier wave is used to transmit a message signal. If the peak voltage of the modulating signal and the carrier signal are increased by $1 \%$ and $3 \%$ respectively,the modulation index is changed by (in $\%$)