1. Transmission Media Overview
Transmission media is the physical pathway through which data is transmitted from one device to another.
- Two Main Types:
- Wired (Guided Media): Data travels through physical cables.
- Wireless (Unguided Media): Data travels through the air without physical cables.
2. Types of Wired (Guided) Media
| Type | Description | Use Cases | Key Features |
|---|
| Twisted Pair Cable | Two insulated copper wires twisted together to reduce interference. | Telephony, LAN connections. | Cheap, flexible, limited bandwidth. |
| Coaxial Cable | Single copper core surrounded by insulating layers. | Cable TV, internet. | Better noise resistance, supports higher speeds than twisted pair. |
| Fiber Optic Cable | Uses light to transmit data through glass or plastic fibers. | High-speed internet, telecom. | Very high bandwidth, immune to EMI, expensive. |
3. Types of Wireless (Unguided) Media
| Type | Description | Use Cases | Key Features |
|---|
| Radio Waves | Electromagnetic waves used for long-distance communication. | FM/AM radio, Wi-Fi. | Low frequency, travels long distances. |
| Microwaves | High-frequency radio waves for point-to-point communication. | Satellite, cellular networks. | Needs line of sight, high bandwidth. |
| Infrared (IR) | Light waves below visible spectrum for short distances. | TV remotes, short-range IoT. | Cannot pass through walls. |
| Satellite | Data transmitted to/from satellites orbiting Earth. | GPS, international calls. | High latency, used for global coverage. |
4. Comparison of Wired and Wireless Media
| Feature | Wired Media | Wireless Media |
|---|
| Installation | Requires cables, complex. | Easier, no physical cables. |
| Cost | Higher (fiber optics). | Lower upfront cost. |
| Speed | Faster (fiber optic). | Slower, depends on technology. |
| Mobility | Limited. | Highly mobile. |
| Interference | Less prone (fiber optics). | More prone (radio waves). |
5. Key Points to Remember
- Twisted Pair: Most common, used in Ethernet cables (Cat-5, Cat-6).
- Coaxial Cable: Used for cable TV, older networks.
- Fiber Optic: Best for long distances and high speed.
- Microwaves: Require line-of-sight; used in satellite and cellular networks.
- Infrared: For very short-range communication.
6. Quick Recap Table
| Media Type | Range | Speed | Cost |
|---|
| Twisted Pair | Short (<100m) | Medium (10 Mbps – 10 Gbps) | Low |
| Coaxial Cable | Medium (<500m) | Medium (10 Mbps – 1 Gbps) | Moderate |
| Fiber Optic | Long (>10 km) | High (1 Gbps – 100 Gbps) | High |
| Radio Waves | Long (>1 km) | Medium | Low |
| Microwaves | Medium (up to 80 km) | High | Moderate |
| Infrared | Short (<10m) | Low | Low |
Types of Transmission Media (Wired and Wireless) – MCQ
1. Which transmission medium provides the highest speed?
- A) Coaxial Cable
- B) Twisted Pair Cable
- C) Optical Fiber
- D) Electrical Cable
- Answer: C) Optical Fiber
2. What type of cable is used for voice and data communications?
- A) Coaxial Cable
- B) Fiber-optic Cable
- C) Twisted Pair Cable
- D) All of the above
- Answer: C) Twisted Pair Cable
3. What is an example of unguided transmission media?
- A) Fiber-optic Cable
- B) Coaxial Cable
- C) Radio Waves
- D) Twisted Pair Cable
- Answer: C) Radio Waves
4. In fiber-optic cables, the signal is transmitted using:
- A) Electrical signals
- B) Infrared light
- C) Light waves
- D) Radio waves
- Answer: C) Light waves
5. Radio waves are:
- A) Omnidirectional
- B) Unidirectional
- C) Bidirectional
- D) Single-direction
- Answer: A) Omnidirectional
6. Which cable consists of a central conductor and an outer shield?
- A) Twisted Pair Cable
- B) Coaxial Cable
- C) Fiber-optic Cable
- D) Ethernet Cable
- Answer: B) Coaxial Cable
7. Which transmission medium uses light signals?
- A) Fiber-optic Cable
- B) Coaxial Cable
- C) Ethernet Cable
- D) Twisted Pair Cable
- Answer: A) Fiber-optic Cable
8. What is a disadvantage of wireless communication compared to wired communication?
- A) Limited bandwidth
- B) High installation cost
- C) Limited mobility
- D) None of the above
- Answer: A) Limited bandwidth
9. Which medium is best for long-distance data transmission with minimal signal loss?
- A) Twisted Pair Cable
- B) Fiber-optic Cable
- C) Coaxial Cable
- D) Radio Waves
- Answer: B) Fiber-optic Cable
10. In an optical fiber, what causes signal propagation?
- A) Refraction
- B) Reflection
- C) Diffraction
- D) Modulation
- Answer: B) Reflection
For more detailed study, refer to resources like ExamRadar, MCQs Mentor, and CSEStudy247.
