easyMultiple Choice
220-1201 Practice Question: A user complains that their VoIP phone…
A user complains that their VoIP phone intermittently loses connectivity. The phone is connected to a switch via a 50-meter run of solid-core Cat6 cable. You suspect interference from nearby fluorescent lights. Which cabling characteristic is most relevant to this issue?
⚠ Common exam trap
In the CompTIA A+ exam, this question tests understanding of how electromagnetic interference (EMI) from sources like fluorescent lights affects UTP cabling and the importance of using shielded twisted-pair (STP). The trap is that candidates may incorrectly attribute the issue to cable length or termination, overlooking that interference is a shielding problem, not a distance or connector issue.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The cable is not shielded (STP).
Fluorescent lights generate electromagnetic interference (EMI), which can disrupt data transmission over unshielded twisted-pair (UTP) cabling. Shielded twisted-pair (STP) cable includes a conductive shield that protects against EMI, making it the relevant characteristic for this issue. The user's intermittent connectivity is likely caused by EMI coupling onto the UTP cable, and using STP would mitigate this.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The cable is not properly terminated with RJ45 connectors.
Why it's wrong here
Poor termination causes intermittent link loss, but the stem already attributes the fault to fluorescent-light interference, which induces noise on the cable rather than at the connector. It is tempting because termination faults are common, yet this would be correct if the symptom followed cable movement rather than proximity to the lights.
- ✓
The cable is not shielded (STP).
Why this is correct
Unshielded twisted-pair cabling lacks the foil or braid that blocks electromagnetic interference, so fluorescent lighting induces noise on the 50-metre run. Shielded (STP) cable would satisfy the requirement to resist that interference and stabilise VoIP connectivity.
- ✗
The cable length exceeds the maximum for Cat6.
Why it's wrong here
Cat6 supports 100-metre runs, so 50 metres is well within specification and cannot explain intermittent loss. It is tempting because length limits are a familiar cabling fault, but this characteristic would be the correct answer if the run exceeded the standard's maximum distance rather than sitting comfortably inside it.
- ✗
The cable is a crossover cable.
Why it's wrong here
A crossover cable affects pin pairing between like devices, but modern switches auto-detect MDI/MDI-X, and it would cause total link failure rather than intermittent dropouts. It is tempting because crossover wiring is a classic connectivity fault, but it would be correct when connecting two switches or two hosts directly without auto-detection.
Visual reference
Go deeper
Related to this question
About these practice questions
This 220-1201 question is part of Courseiva's 871-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 220-1201 practice question is part of Courseiva's free CompTIA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 220-1201 exam.