In communication system, only one percent frequency of signal of wavelength 900 nm can be used as band width. How many channel of 6MHz band width can broadcast this? c=3×108m/s, h=6.6×10−34J−s

Here signal wavelength, λ=900nm=9×10−7m  Frequency of source is  f=cλ=3×1089×10−7=3.33×1014Hz ∴Total band width used for communication= 1 % of  3.33×1014Hz =3.33×1012   So, number of channels for signals  =total bandwidth available for communicationbandwidth of T.Vsignal                                                                       =3.33×10126×106=5.55×105