Transmission media (wired, wireless) in Computer Networks - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is transmission media in computer networks?

Transmission media is the physical path or channel through which data travels from one device to another in a network.

beginner

Name two main types of transmission media.

The two main types are wired (guided) media and wireless (unguided) media.

beginner

Give an example of wired transmission media.

Examples include twisted pair cables, coaxial cables, and fiber optic cables.

beginner

What is wireless transmission media?

Wireless transmission media uses air or space to transmit data signals without physical cables, such as radio waves, microwaves, and infrared.

intermediate

Why might wireless media be preferred over wired media?

Wireless media allows mobility, easier installation, and can cover large areas without cables, but may be less secure and more prone to interference.

Which of the following is NOT a type of wired transmission media?

A Radio waves

B Twisted pair cable

C Fiber optic cable

D Coaxial cable

Radio waves are a form of wireless transmission media, not wired.

What type of transmission media uses air to send signals?

A Wireless media

B Fiber optic cable

C Twisted pair cable

D Coaxial cable

Wireless media transmits data through air or space without cables.

Which wired media offers the highest speed and least signal loss?

A Coaxial cable

B Fiber optic cable

C Twisted pair cable

D Infrared

Fiber optic cables use light to transmit data, providing very high speed and low loss.

Which is a disadvantage of wireless transmission media?

A Requires physical cables

B Limited mobility

C Susceptible to interference

D Difficult to install

Wireless signals can be affected by interference from other devices or obstacles.

Which transmission media is best for long-distance, high-speed communication?

A Twisted pair cable

B Radio waves

C Infrared

D Fiber optic cable

Fiber optic cables are ideal for long distances and high-speed data transfer.

Explain the difference between wired and wireless transmission media.

Think about how data travels physically in each type.

List common examples of wired transmission media and describe one key feature of each.

Focus on what makes each cable type unique.

Practice

1. Which of the following is an example of a wired transmission medium?

easy

A. Radio waves

B. Microwaves

C. Infrared signals

D. Twisted pair cable

Solution

1. Step 1: Understand wired media

   Wired media use physical cables to carry signals between devices.

2. Step 2: Identify examples

   Twisted pair cable is a common wired medium, while radio, infrared, and microwaves are wireless.

3. Final Answer:

   Twisted pair cable -> Option D

4. Quick Check:

   Wired media = cables like twisted pair [OK]

Hint: Wired media always use cables, wireless use airwaves [OK]

Common Mistakes:

• Confusing wireless signals as wired
• Thinking infrared uses cables
• Mixing radio waves with cables

2. Which of the following correctly describes wireless transmission media?

easy

A. Uses cables like coaxial and fiber optic

B. Uses airwaves such as radio and infrared

C. Requires physical connection between devices

D. Only works indoors

Solution

1. Step 1: Define wireless media

   Wireless media transmit data through air without cables.

2. Step 2: Identify correct examples

   Radio waves and infrared are common wireless transmission methods.

3. Final Answer:

   Uses airwaves such as radio and infrared -> Option B

4. Quick Check:

   Wireless = airwaves like radio, infrared [OK]

Hint: Wireless means no cables, uses airwaves [OK]

Common Mistakes:

• Choosing cable-based options
• Thinking wireless needs physical wires
• Assuming wireless only works indoors

3. Consider the following code snippet describing transmission media types:

media = ['Twisted Pair', 'Radio', 'Fiber Optic', 'Infrared']
wired = [m for m in media if 'Fiber' in m or 'Twisted' in m]
print(wired)

What will be the output?

medium

A. ['Twisted Pair']

B. ['Radio', 'Infrared']

C. ['Twisted Pair', 'Fiber Optic']

D. ['Fiber Optic']

Solution

1. Step 1: Understand list comprehension filter

   The code selects items containing 'Fiber' or 'Twisted' from the media list.

2. Step 2: Identify matching items

   'Twisted Pair' and 'Fiber Optic' both match the condition, so they are included.

3. Final Answer:

   ['Twisted Pair', 'Fiber Optic'] -> Option C

4. Quick Check:

   Filter for wired media = ['Twisted Pair', 'Fiber Optic'] [OK]

Hint: Look for keywords 'Fiber' or 'Twisted' in list items [OK]

Common Mistakes:

• Selecting wireless items by mistake
• Ignoring 'Fiber' keyword
• Confusing list output format

4. A student wrote this statement about transmission media: "Fiber optic cables use radio waves to transmit data." What is wrong with this statement?

medium

A. Fiber optic cables use light, not radio waves

B. Fiber optic cables are wireless

C. Radio waves cannot carry data

D. Fiber optic cables use electrical signals only

Solution

1. Step 1: Understand fiber optic transmission

   Fiber optic cables transmit data using light signals inside glass fibers.

2. Step 2: Compare with radio waves

   Radio waves are wireless signals traveling through air, not inside cables.

3. Final Answer:

   Fiber optic cables use light, not radio waves -> Option A

4. Quick Check:

   Fiber optic = light signals, not radio waves [OK]

Hint: Fiber optic uses light, radio waves are wireless [OK]

Common Mistakes:

• Thinking fiber optic uses radio waves
• Confusing wireless and wired media
• Assuming fiber optic uses electricity only

5. A company wants to set up a network in a large building with many walls and floors. They want fast data speeds and minimal interference. Which transmission media should they choose?

hard

A. Fiber optic cables for high speed and low interference

B. Twisted pair cables for low cost

C. Infrared signals for secure communication

D. Wireless radio waves for easy setup

Solution

1. Step 1: Analyze company needs

   They want fast speeds and minimal interference in a large building.

2. Step 2: Evaluate media options

   Wireless radio waves can face interference and walls block signals; twisted pair is slower and less reliable over long distances; infrared requires line of sight; fiber optic offers high speed and low interference through cables.

3. Final Answer:

   Fiber optic cables for high speed and low interference -> Option A

4. Quick Check:

   Best for speed and interference = fiber optic cables [OK]

Hint: For speed and low interference, choose fiber optic cables [OK]

Common Mistakes:

• Choosing wireless despite interference
• Ignoring speed differences
• Assuming infrared works through walls