Tricky Exam Question

[bphgravity]

A student at a recent seminar I held came at me with this question that was on the Experior Master exam he had taken just a couple weeks ago.

Anyone want to give it a shot?

What size PVC sch 40 conduit would be required for two 3-phase circuits sharing a common equipment grounding conductor. Load 1 is at 30-amp, Load 2 is a at 50-amps. The ambient temperature is 124 degrees F. and both loads are continuous.

[ June 23, 2003, 06:50 PM: Message edited by: bphgravity ]

 

[roger]

Re: Tricky Exam Question

Bryan, before we rack the ol brains, are you sure there wasn't insulation type or terminal ratings in the question?

Roger

 

[bphgravity]

Re: Tricky Exam Question

75 degree terminations and thhn/thwn conductors.

Thanks.

 

[roger]

Re: Tricky Exam Question

1.25 if the wording is correct.

Roger

 

[bphgravity]

Re: Tricky Exam Question

Wow! Thats exactly what I got until I read Article 352.12(D).

I tell you, these exam questions are getting more about trickery than they are about electrician competency!!!

 

[skd76]

Re: Tricky Exam Question

That seems like a patently unfair question for a license/certification exam. It would be a candidate for a challenge *UNLESS* there was a multiple choice answer that read something like..."The code would prohibit this installation.". In that case it would seem to me, to be an appropriate test question.

 

[bphgravity]

Re: Tricky Exam Question

The Experior Exam does give a multiple choice selection, 5 choices. And yes, one was "not permitted by code."

My point is that the exams are indeed not fair. A calculation question should be designed to test the exam takers ability to understand the requirement and apply the applicable formula and tables.

This question shows that the user can indeed follow the rules and requirements for calcualting total loads and conduit fill, just to be railroaded with an obscure code requirement.

Getting this question wrong by given the value that technicaly would be allowed is a crime. Experior is not regulated by any state or local licensing boards here in the state of Florida. They have complete control over content and types of questions used.

How can a for-profit exam provider by honestly used for proper assement of ones abilities?

 

[skd76]

Re: Tricky Exam Question

I have read many posts challenging the motivation and fairness of Experior testing. Your position may well be the correct one in that regard - I don't know where I stand on that issue just yet.

The point that stood out to me on the example was that the question fairly tested the examinee's methodology. Each real-world situation should include examination of what is an allowed use of a specific method or material BEFORE expending time, money, energy in a particular material or method. The same techniques are advisable for a test question PARTICULARLY when one of the answers is "Not allowed by code.". The NEC is written that way as well. What IS and IS NOT allowed for a particular item is in section 2,3 or 4 of each part of chapter three. That info precedes the specific rules that follow. It should be considered early on.

I do understand your frustration at "unfair" questions. This one, I feel, is more fair that than not.

[ June 24, 2003, 11:04 AM: Message edited by: skd76 ]

 

[pam]

Re: Tricky Exam Question

I have been studying for my inspectors test and I got caught between the changing of the code, so I have been using study materials from 1999 and using the 2002 codebook. I check the answer I get and if it isnt right I go to 1999 to see what changed. I have discovered that #8 THW has changed sizes when it went from 1999 to 2002. It used to be with RHH, etc.. Does anyone have any input?

 

[roger]

Re: Tricky Exam Question

Oops!

Bryan, I agree that this type of question is bogus and a waste of effort if this was soley for trickery. I am also in total agreement that someone who can show the skills of the calcs should not have to worry about being tricked. I thought about asking for the multiple choice answers when I asked whether insulation and terminals were mentioned. But, the wording,

What size PVC sch 40 conduit would be required

could be interpreted as meaning if it were allowed.

I'm not saying I caught this, I did as you did, but with this particular answer red flaged, most would look a little farther into the question.

Roger

 

[bennie]

Re: Tricky Exam Question

This question is similar to the old one...What is the ampacity of a 500 kcmil TW conductor in an ambient temperature of 140?F?

 

[peter]

Re: Tricky Exam Question

352.12 D?
Will somebody please clue me in? I don't have have the 2002 edition of the Code but have the '99 Handbook and '96.
352 is about metalic raceways like wiremold.
~Peter

 

[pierre]

Re: Tricky Exam Question

Hello Bryan

I teach a test prep class, and our area uses Experior. One of the ways that I prep these guys is in using the Code and not memorizing it. In that way I tell them when a wiring method is mentioned in the question to always go to the Article mentioned (since they are so short) and glance over them. This eliminates alot of those type of mistakes. Not only that, but when they use a question with an oddball temp, I always tell them it should make them aware it is a 'trick question'. Even though I do not think there are any trick questions. Towards the end of the class I fire questions at them and time them, it is fun and really makes them think about the question. We cannot know it all, but we can sure try.BTW- one of these posts someone mentioned 'expert'. There is soooooooooo much to know, it is scarey. That is the benefit of this forum, where years ago it was not available and information was harder to get.

Pierre

 

[iwire]

Re: Tricky Exam Question

Peter here is 352.12(D) it tells us that PVC is not allowed at the temperature listed in the question.

2002 NEC

352.12 Uses Not Permitted.
RNC shall not be used in the following locations.

(D) Ambient Temperatures. Where subject to ambient temperatures in excess of 50?C (122?F) unless listed otherwise.

 

[charlie b]

Re: Tricky Exam Question

I also calculated a result of 1.25?, thereby also falling into the trap. In retrospect, there was a glaring clue that should have alerted me to the possibility that this might have been a trick question. The question threw nine facts on the table, every one of which could influence the result. That is a great deal to deal with, on a single test question. The presence of that many factors should have made me, at the very least, suspicious.

 

[bennie]

Re: Tricky Exam Question

Another dumb test question...Which of the following wire sizes can be paralleled, Size 0 or 1/0?

 

[bphgravity]

Re: Tricky Exam Question

My assumption is that this student was actually testing to see my knowledge of code and code required calculations, and probably was not on a real exam. There is always one student that tries to pull one over the instructor. I guess it is human nature?

However, it is not uncommon for exam providers to require several operations in one question. This way they get to really ask several questions for every one actual question. My estimation is that for a 100 question Master exam actuall consists of nearly 150 questions. This is do to multi-operation questions that could have been asked individually but are combined for added complication and time consumption.

The bottom line is knowing how to take an exam and expecting to be tricked is just as important as preparation on actual exam content.

 

[pierre]

Re: Tricky Exam Question

Bryan

I read your post again, and you mentioned that it is a calculation question. This is a common way that they try to confuse the test taker, but it is not a calculation question. Some of the guys in my class will call after the test and say that there were a lot of calculation questions for the same reason. The calculation questions on the test are relatively short, with only one or two longer ones. Sometimes they even confuse looking up a table value as a calculation question. My experience with the test is the calculation questions are 'mostly' fair, it is some of the 'oddball' questions they ask, that drive a person up the wall.
Another thing about the test is the calculation questions are worth the same as a simple question, because of this I tell them not to get'hung-up' on the calc questions.

Pierre

 

[luke warmwater]

Re: Tricky Exam Question

Originally posted by bphgravity:
There is always one student that tries to pull one over the instructor. I guess it is human nature?

Bryan, I've recently hired a new guy who was in electrical school. After talking to him for a while one day, he started to ask me questions about Code. But he asked in such a way that it seemed as if he was testing my knowledge.

He seemed amazed that I answered him with Code articles. (so did I)

Thanks to all on this site who share their knowledge!!

 

[brian john]

Re: Tricky Exam Question

Not sure if this qualifies as a trick question, but defiantly an involved question that requires some looking. If multiple choice I would (I'd like to think) work backwards based upon available answers, depending on the timeframe of course. A master exam should IMHO test one’s ability.