Which statement about EMI in fiber-optic cabling is most accurate?

Which statement about EMI in fiber-optic cabling is most accurate?

• A. They are more prone to EMI than copper
• B. They require shielding
• C. They experience significantly less EMI because they are non-conductive
• D. They have no EMI whatsoever

Answer: (C)

EMI stands for electromagnetic interference, and fiber-optic cables carry signals as light in a glass or plastic core rather than as electrical current. Because there’s no conductor carrying the signal, external electromagnetic fields don’t couple into the transmission the way they do with copper. That’s why fiber experiences significantly less EMI. It’s not accurate to say there’s no EMI at all, since electronics at the transmitter and receiver can still be affected by EMI, but the fiber itself is largely immune to electrical noise. The other statements are not correct because copper is more susceptible to EMI, shielding isn’t typically needed purely to combat EMI in the fiber path, and claiming no EMI whatsoever is an overstatement.

EMI stands for electromagnetic interference, and fiber-optic cables carry signals as light in a glass or plastic core rather than as electrical current. Because there’s no conductor carrying the signal, external electromagnetic fields don’t couple into the transmission the way they do with copper. That’s why fiber experiences significantly less EMI. It’s not accurate to say there’s no EMI at all, since electronics at the transmitter and receiver can still be affected by EMI, but the fiber itself is largely immune to electrical noise. The other statements are not correct because copper is more susceptible to EMI, shielding isn’t typically needed purely to combat EMI in the fiber path, and claiming no EMI whatsoever is an overstatement.