Question 1
A hospital network administrator needs to connect two buildings 600 metres apart. One building houses an MRI machine and other high-powered electrical equipment. Which transmission medium is most appropriate for this inter-building link, and why?No clue? Show me the answer
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Method #1Direct approachStep 1: Identify the key constraints
The link must cover 600 metres and operate near high-powered electrical equipment such as an MRI machine, which generates significant electromagnetic interference (EMI).
Step 2: Apply the range criterion
Twisted pair cables are limited to approximately 100 metres per segment before signal degradation requires a repeater. A 600-metre run would need multiple repeaters, increasing cost and complexity.
Step 3: Apply the EMI criterion
Fibre optic cables transmit data as pulses of light, which are completely unaffected by electrical fields. They are immune to EMI, making them ideal for environments with heavy electrical machinery.
Step 4: Apply the attenuation criterion
Fibre optic cables have very low attenuation, meaning signal strength is maintained effectively over 600 metres without boosters.
Step 5: Select the correct answer
Fibre optic cable is the correct choice because it handles both the distance (low attenuation) and the interference (EMI immunity) requirements of this scenario.
Method #2Process of EliminationStep 1: Identify what is being tested
This question tests knowledge of transmission media characteristics — specifically range, EMI susceptibility, and attenuation — applied to a real-world hospital scenario.
Step 2: Eliminate UTP twisted pair
"UTP twisted pair cable, because it is inexpensive and easy to install" is wrong. UTP is limited to ~100 metres per segment and is susceptible to EMI — both serious problems here. Cost and ease do not outweigh these technical limitations.
Step 3: Eliminate wireless transmission
"Wireless transmission, because no physical cable needs to be laid" is wrong. Wireless is highly susceptible to interference from electrical equipment and has variable reliability — a critical concern in a hospital environment.
Step 4: Eliminate STP twisted pair
"STP twisted pair cable, because the metallic shielding completely eliminates all forms of signal interference" is wrong. STP provides better EMI protection than UTP but does not completely eliminate interference, and it still has the 100-metre range limitation.
Step 5: Select the correct answer
The remaining option — fibre optic cable — is correct because it is immune to EMI and supports long-distance transmission with minimal signal loss.
Question 2
A network engineer compares fibre optic cables and twisted pair cables for a new office LAN. Which statement most accurately describes the difference in their installation complexity?No clue? Show me the answer
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Method #1Direct approachStep 1: Identify the criterion being compared
The question specifically asks about installation complexity, one of the eight key factors for comparing transmission media.
Step 2: Recall twisted pair installation characteristics
Twisted pair cables use standard RJ-45 connectors, are widely understood by technicians, and can be installed without specialist tools. This makes installation low complexity.
Step 3: Recall fibre optic installation characteristics
Fibre optic cables require specialised tools (e.g. fusion splicers) and trained technicians to handle the fragile glass fibres. Improper handling can damage the cable, making installation high complexity.
Step 4: Select the correct answer
The correct answer is that twisted pair cables are easier to install due to standard connectors and no specialist skill requirement.
Method #2Process of EliminationStep 1: Identify what is being tested
This question tests knowledge of installation complexity as a comparative factor between fibre optic and twisted pair cables.
Step 2: Eliminate the 'fibre is easier' option
"Fibre optic cables are easier to install because they are lighter and more flexible" is wrong. Fibre optic cables are fragile and require specialised splicing tools and trained personnel — they are notably harder to install.
Step 3: Eliminate the 'identical complexity' option
"Both media have identical installation complexity" is wrong. There is a clear difference: fibre optic installation requires specialist equipment and skills that twisted pair does not.
Step 4: Eliminate the 'twisted pair is harder' option
"Twisted pair cables are harder to install because each pair must be individually shielded" is wrong. Individual shielding is a feature of STP, and even STP is considerably easier to install than fibre optic. UTP requires no shielding at all.
Step 5: Select the correct answer
The correct answer is that twisted pair cables are easier to install, using standard connectors and requiring no specialist skills.