Question

The loss in single-mode fiber optic cable due to the splice is about ________

(a) 0.2 dB per km

(b) 0.02 dB per km

(c) 0.0002 dB per km

(d) 2 dB per km

This question was addressed to me during an internship interview.

This key question is from Noise in Pulse Modulated System in chapter Phase Locked Loop & Pulse Modulation of Analog Communications

Answer 1

Right answer is (b) 0.02 dB per km

For explanation: A fiber-optic cable consist of a bundle of glass threads, each of which is capable of transmitting messages. The loss in single-mode fiber optic cable due to the splice is about 0.02 dB per km. In single mode fiber optical cable, only a single light ray is transmitted.