An optical fibre communication system works on a wavelength of 1.3 m . The number of subscribers it can feed, if a channel requires 20 kHz are

Step-by-step solution

The frequency of the optical signal is given by = c , where c = 3 10^8 m/s and = 1.3 10⁻⁶ m . = 3 10^8 1.3 10⁻⁶ 2.3 10¹⁴ Hz . The number of subscribers N is the ratio of the total bandwidth to the bandwidth per channel. Assuming the total bandwidth is approximately equal to the carrier frequency: N = = 2.3 10¹⁴ 20 10^3 = 2.3 10¹⁴ 2 10^4 = 1.15 10¹⁰ . Answer: 1.15 10¹⁰