easyMultiple ChoiceObjective-mapped
220-1201 Practice Question: A small office has intermittent network dropouts
A small office has intermittent network dropouts. A technician suspects electromagnetic interference (EMI) from nearby fluorescent lights affecting the unshielded twisted-pair (UTP) cables. Which tool can best confirm the presence of EMI on the cable?
⚠ Common exam trap
The CompTIA A+ exam often tests the distinction between tools that verify physical-layer compliance (certifier) versus tools that only indicate symptoms (ping) or operate on different media (Wi-Fi analyzer), leading candidates to mistakenly choose ping because it shows packet loss during dropouts.
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
✓
Cable certifier
A cable certifier is the correct tool because it can measure crosstalk, return loss, and other electrical characteristics that reveal the presence of EMI on UTP cables. Unlike simple continuity testers, a certifier performs frequency-domain analysis (e.g., up to 500 MHz for Cat6a) to detect noise and interference that cause intermittent dropouts.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Tone generator
Why it's wrong here
A tone generator, often used in conjunction with an inductive probe, is primarily designed for tracing and identifying specific cables within a bundle or wall. It injects an audible signal onto a cable, allowing a technician to physically locate and label the correct wire. However, this tool provides no diagnostic capability regarding signal quality, noise levels, or electromagnetic interference (EMI) that could cause intermittent network dropouts.
- ✓
Cable certifier
Why this is correct
A cable certifier is a sophisticated diagnostic tool specifically engineered to perform comprehensive tests on network cabling, ensuring it meets TIA/ISO industry standards. It can precisely measure critical parameters such as signal attenuation, near-end crosstalk (NEXT), far-end crosstalk (FEXT), return loss, and, crucially, noise levels and external electromagnetic interference (EMI). By quantifying these factors, a certifier can definitively identify whether external sources like fluorescent lights or machinery are degrading signal integrity on UTP cables, leading to intermittent connectivity issues.
- ✗
Ping
Why it's wrong here
The ping utility is a fundamental network command-line tool used to test basic IP connectivity and measure round-trip time to a destination host. While it can reveal packet loss, which might indicate a problem, ping operates at the network layer and cannot diagnose the underlying physical layer cause of that loss. It cannot differentiate whether packet loss is due to EMI, a faulty network interface card, a misconfigured router, or a congested link, making it insufficient for pinpointing the specific cause of intermittent dropouts related to cable quality.
- ✗
Wi-Fi analyzer
Why it's wrong here
A Wi-Fi analyzer is a specialized software or hardware tool designed exclusively for diagnosing and optimizing wireless local area networks (WLANs). It monitors Wi-Fi signals, identifies available SSIDs, assesses channel utilization, measures signal strength, and detects interference within the 2.4 GHz and 5 GHz wireless frequency bands. This tool is entirely irrelevant for troubleshooting issues on a wired UTP (Unshielded Twisted Pair) cable network, as it cannot detect or analyze physical layer problems or EMI affecting copper cabling.
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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.