A twisted pair helps reduce electromagnetic interference by

• A. Inverting the signal
• B. Balancing the lines and canceling interference
• C. Increasing impedance
• D. Reducing current

Answer: (B)

Twisted pair reduces electromagnetic interference by creating balanced lines. The two conductors carry the signal in opposite directions so the receiver reads the difference between them (differential signaling). External noise tends to affect both wires equally, producing a similar voltage on each line (common-mode). When the receiver subtracts one wire from the other, that common-mode noise cancels out, while the actual signal—the difference between the two wires—remains. The twisting also helps keep the wires’ impedance matched and the loop area small, which further minimizes interference.