To radiate a wave of frequency $1 \text{ kHz}$ efficiently,what should be the minimum length of the antenna in $km$?

An $AM$ wave has $1800 \ W$ of total power content. For $100 \%$ modulation,the carrier should have a power content equal to $...... \ W$.

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?

The radius of the Earth is $6400 \text{ km}$. If the height of the antenna is $500 \text{ m}$, then its range is: (in $\text{ km}$)

If the maximum and minimum voltage of an $AM$ wave are $V_{max}$ and $V_{min}$,then the modulation index is given by:

An audio signal $v_{m} = 20 \sin(2 \pi \times 1500 t)$ amplitude modulates a carrier $v_{c} = 80 \sin(2 \pi \times 100,000 t)$. The value of percent modulation is..........