Twisted wires are used to:

• A. Increase data rate
• B. Cancel out EMI
• C. Reduce resistance
• D. Absorb heat

Answer: (B)

Twisted wires are used to cancel out EMI by reducing the effect of external electromagnetic interference on the signal. The twists cause the two conductors in a pair to pick up similar noise from the surrounding environment. When the signal is read with a differential receiver, it looks at the difference between the two wires, so the common noise tends to cancel out. This keeps the actual data signal cleaner and more reliable, especially over longer distances or in noisy environments.

Twisting doesn’t inherently increase data rate by itself, since data rate depends on bandwidth and signaling methods. It also doesn’t reduce resistance, which is determined mainly by the conductor material and gauge, nor does it absorb heat in a meaningful way.