Figure shows a communication system. Which is the output power when input signal is 1.01 mW? (Gain in dB=\(10\log { _{ 10 }\frac { { P }_{ 0 } }{ { P }_{ 1 } } } \))

Consider an optical communication system operating at = 800nm. Suppose only 1% of optical source frequency is the available channel bandwidth for optical communication. How many channels can be accommodated for transmitting 
(i) audio signals requiring a bandwidth of 8kHz?
(ii) video TV signals requiring an approximate bandwidth of 4.5MHz? Support your answer with suitable calculations.

An audio signal is modulated by a carrier wave of 20 MHz such that the bandwidth required for modulation is 3kHz.Could this wave be demodulated by a diode detector which has the values of R and C as
 (i) R=\(1k\Omega ,C=0.01\mu F\)
 (ii) R=\(10k\Omega ,C=0.01\mu F\)
 (iii) R=\(10k\Omega ,C=1\mu F\)

(i) Draw the plot of amplitude versus for an amplitude modulated wave whose carrier wave(\({ \omega }_{ c }\) ) is carrying two modulating signals, \({ \omega }_{ 1 }\) and\({ \omega }_{ 2 }\)
(ii) Is the plot symmetrical about \({ \omega }_{ c }\)?Comment especially about plot in region \(\omega <\omega _{ c }\)
(iii) Extrapolate and predict the problems, one can expect if more waves are to be modulated
(iv) Suggest solution to the above problem. In the process can one understand another advantage of modulation in terms of bandwidth?

An amplitude modulated wave is as shown in the figure.Calculate
(i) the percentage modulation
(ii) peak carrier voltage and 
(iii) peak value of information voltage.