How would you use a multimeter to determine a wire pair on 100 block in another room?

rpenri · December 2011

Hi, I've been taking practice tests for the Network+ and I see this question a lot but I haven't the slightest clue as to how this is done.

So the question is: How do you use a multimeter to determine a wire pair running from a jack to the 100 block it's terminated at in another room?

How exactly do you determine which wire is which by using a multimeter? The multimeter tests for voltage and continuity as well as resistance...but wouldn't a toner probe be better?

Thanks,

Darril · December 2011

Great first post. You are correct that a toner probe is the correct tool to use. While a multimeter can measure continuity, there's no way to connect the two probes of the multimeter to cable ends in two rooms. However, a toner probe has two elements. One places a tone on one end of the cable. You take the probe to the other room and when you touch it to the cable with the tone, it plays the tone on the speaker. A search on Google of "toner probe" and clicking Images shows several pictures.

One of the things to look for in quality practice tests is good explanations of why the correct answer is correct, and why the incorrect answers are incorrect. Otherwise, you could end up memorizing bogus information.

HTH,

Darril Gibson
Security+ Blog
Security+ Tip of the Day

rpenri · December 2011

Thanks, you've confirmed what I was thinking.

I know that I need to find better practice questions, but there are so many out there that it's hard to know which one is good and which ones aren't. I guess I will have to keep looking.

drkat · December 2011

the only way this would work is if you're testing for a short or open

dead_p00l · December 2011

drkat wrote: »

the only way this would work is if you're testing for a short or open

Or if you had a loopback plug to complete the circuit.

How would you use a multimeter to determine a wire pair on 100 block in another room?

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