If the amplitude of an audio signal is half the amplitude of the carrier wave,what is the modulation index?

The total power in an $AM$ wave is $1500 \ W$. What is the power transmitted by the carrier for $100\%$ modulation (in $W$)?

The maximum amplitude of an $AM$ wave is found to be $20 \,V$ while its minimum amplitude is $4 \,V$. The modulation index is

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?

This question has Statement-$1$ and Statement-$2$. Of the four choices given after the statements, choose the one that best describes the two statements.
Statement-$1$: Sky wave signals are used for long-distance radio communication. These signals are, in general, less stable than ground wave signals.
Statement-$2$: The state of the ionosphere varies from hour to hour, day to day, and season to season.

An amplitude modulated signal is plotted below. Which one of the following best describes the above signal?