In optical fibre, propagation angle of light must be less than or equal to
Important Questions on Communication Systems
A modulated signal is represented as $x(t)=6 \sin 1250 t+\sin 10^{8} t$ then the modulating index is
The number of AM broadcast stations that can be accommodated in a $300 \mathrm{kHz}$ bandwidth for the highest modulating frequency $15 \mathrm{kHz}$ will be
The audio signal used to modulate $30 \sin \left(2 \pi \times 10^{6} \mathrm{t}\right)$ is $15 \sin 300 \pi \mathrm{t}$. The depth of modulation is
If a number of sine waves with modulation indices $n_{1}, n_{2}, n_{3} \ldots \ldots \ldots$ modulate a carrier wave, then the total modulation index (n) of the wave is
In space communication, the information can be passed from one place to another at a distance of in
The maximum usable frequency in F-layer with the original frequency of will be
