Data communication
Why?
Why are network cable wires twisted?
Why are the wires inside your Ethernet cable twisted together?
Quick check · tap an answer to continue
Lesson notes
Key points
- Because nearby noise induces voltage into any wire, corrupting the signal it carries.
- Because the pair sends the signal differentially, the receiver reads only the difference between the two wires.
- Because twisting swaps each wire's position constantly, both wires pick up nearly equal noise, which then cancels.
Definitions
- Electromagnetic interference
- Unwanted voltage induced in a conductor by external electric or magnetic fields.
Takeaway: So twisting makes noise equal on both wires, and subtraction cancels it.
Quick check: How does the receiver remove noise on a twisted pair?
- It amplifies both wires
- It takes their difference
- It adds both signals
Equal noise on both wires disappears when subtracted.
Induced noiseDifferential signalEqual exposure
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