---
title: "Compare twisted pair, coaxial, fiber"
subject: "Computer Networks and Security"
chapter: 2
key: "semester_7/computer_networks_and_security:compare-twisted-coax-fiber"
source: https://www.bctengineer.com/q/semester_7/computer_networks_and_security/compare-twisted-coax-fiber
site: BCT Engineering
---

# Compare twisted pair, coaxial, fiber

Computer Networks and Security · Chapter 2: Physical Layer

- Asked in: 2074 Chaitra, 3+5 marks
- Video: [WHAT ARE THE DIFFERENCE BETWEEN TWISTED PAIR CABLE, COAXIAL CABLE AND OPTICAL FIBER CABLE](https://www.youtube.com/watch?v=vosh07X6Wdw) — Auxilectrical Tv
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_7/computer_networks_and_security/compare-twisted-coax-fiber
- Whole chapter: https://www.bctengineer.com/md/semester_7/computer_networks_and_security/chapter-2

## Question

Define transmission media. Compare among twisted pair, coaxial cable and fiber optic.

## Short answer

Twisted pair uses copper wires, electrical signals, low bandwidth, short distance, and is cheapest. Coaxial cable uses shielded copper, medium bandwidth and distance, good EMI immunity. Fiber optic uses light, very high bandwidth, long distance, immune to EMI, but expensive and difficult to install.

## Answer

#### Transmission media
Transmission media is the physical path (cable) or wireless channel that carries data signals between sender and receiver. It is either guided (twisted pair, coaxial, fibre) or unguided (radio, microwave, infrared).

#### Comparison
| Point | Twisted pair | Coaxial cable | Fibre optic |
|---|---|---|---|
| Construction | Two twisted copper wires | Copper core, insulator, shield, jacket | Glass/plastic core and cladding |
| Signal | Electrical | Electrical | Light |
| Bandwidth / data rate | Low (up to 1 to 10 Gbps for Cat6/6a) | Medium (up to about 500 Mbps to 1 Gbps) | Very high (Tbps) |
| Max distance without repeater | About 100 m | 185 m (thinnet) to 500 m (thicknet) | Many km |
| Attenuation | High | Medium | Very low |
| EMI immunity | Poor (UTP), better (STP) | Good | Immune |
| Security | Easy to tap | Moderate | Hard to tap |
| Cost | Cheapest | Medium | Most expensive |
| Installation | Easy, flexible | Moderate, bulky | Difficult, needs special tools |
| Connector | RJ-45 | BNC | SC, ST, LC |
| Use | LAN, telephone | Cable TV, old Ethernet | Backbone, long-haul, ISP |

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Which medium carries light signals?
   A. Twisted pair
   B. Coaxial cable
   C. Fibre optic
   D. All three
   Answer: C. Twisted pair and coax carry electrical signals; fibre carries light. (Key point: Signal type)

2. Which pairing of max distance without repeater is correct?
   A. Twisted pair about 100 m; fibre many km
   B. Twisted pair many km; fibre 100 m
   C. Coaxial many km; fibre 185 m
   D. All same
   Answer: A. Twisted pair is about 100 m, coax 185-500 m, fibre many km. (Key point: Distance)

3. Which is most expensive and immune to EMI?
   A. Twisted pair
   B. Coaxial
   C. Fibre optic
   D. UTP
   Answer: C. Fibre is the costliest and immune to electromagnetic interference. (Key point: EMI immunity and cost)

4. Which connector goes with which?
   A. Twisted pair: BNC; coax: RJ-45
   B. Twisted pair: RJ-45; coax: BNC; fibre: SC/ST/LC
   C. Fibre: RJ-45
   D. Coax: SC
   Answer: B. RJ-45 for twisted pair, BNC for coax, SC/ST/LC for fibre. (Key point: Connectors)

## Related in Computer Networks and Security

- [Guided and other transmission media](https://www.bctengineer.com/question.md?key=semester_7%2Fcomputer_networks_and_security%3Atransmission-media-explain) — Computer Networks and Security, chapter 2, asked 3×
- [Define transmission media](https://www.bctengineer.com/question.md?key=semester_7%2Fcomputer_networks_and_security%3Adefine-transmission-media) — Computer Networks and Security, chapter 2, asked 2×

## Related in other subjects

- [Radio signal in twisted pair and coaxial cable](https://www.bctengineer.com/question.md?key=semester_8%2Ftelecommunications%3Aradio-signal-twisted-coaxial) — Telecommunications, chapter 2
- [Optical fiber advantages over coax and twisted pair](https://www.bctengineer.com/question.md?key=semester_5%2Fdata_communication%3Afiber-advantages) — Data Communication, chapter 4, asked 3×
- [Fiber optic vs copper cable](https://www.bctengineer.com/question.md?key=semester_8%2Ftelecommunications%3Afiber-vs-copper-applications) — Telecommunications, chapter 2
- [Coaxial cable vs optical fiber](https://www.bctengineer.com/question.md?key=semester_5%2Fdata_communication%3Acoax-vs-fiber) — Data Communication, chapter 4