For efficient transmission of sound waves of wavelength $\lambda$,the minimum length of the antenna should be.....

$A$ carrier signal of frequency $1.5 MHz$ has an amplitude of $50 V$. It is amplitude modulated by a modulating wave of frequency $10 kHz$ with a modulation index of $50 \%$. What are the frequencies of the $LSB$ and $USB$?

If multiple waves with modulation indices $n_1, n_2, n_3, ...$ modulate a carrier wave,what is the total modulation index of the resulting wave?

The ionosphere acts as a reflector for which frequency range?

In an amplitude modulator circuit,the carrier wave is given by $C(t) = 4 \sin(20000 \pi t)$ and the modulating signal is given by $m(t) = 2 \sin(2000 \pi t)$. The values of the modulation index and the lower sideband frequency are:

Which type of propagation is used to transmit radio waves from one place to another?