📝 Wavelength Division Multiplexing Technique

Q1. What does FDM stand for?

💡 Difficulty: easy | ✅ Correct: A

Q2. Given that digital signals are first converted to analog before FDM, what would be the effect of using a low‑pass filter with cutoff below the lowest carrier frequency?

💡 Difficulty: medium | ✅ Correct: D

Q3. Suppose three channels are spaced 20 nm apart in wavelength, centered at 1550 nm, 1570 nm, and 1590 nm. If the source drifts by +5 nm, which channel(s) will experience overlap?

💡 Difficulty: hard | ✅ Correct: B