In optical communication system operating at 1200nm, only 2% of the source frequency is available for TV t ransmission having a bandwidth of 5 MHz. the number of TV channels that can be transmitted is

Answer

6

Explanation

The frequency of optical communication is given by,
`v = c/lambda` or `v = (3 xx 10^(8))/(1200 xx 10^(-9))`
`v = 25 xx 10^(13) Hz`
But only 2% of the source frequency is available for TV transmission.
`v = 2.5 xx 10^(14) xx 2%`
`v = 2.5 xx 10^(14) xx 2/100`
`v = 5 xx 10^(12)` Hz
`therefore` Number of channels = `v/("bandwidth")`
No. of channels `= (5 xx 10^(12))/(5 xx 10^(6)) 10^(6)`