Mike Holt's Online 2005 J-Man Test

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George Stolz

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Staff member
Location
Windsor, CO NEC: 2017
Occupation
Service Manager
Well, I took the online prep exam Mike Holt offers, here's how I did:
Module 1. ? Practical Electrical Theory PART 1
Questions 1 - 25 of 100 ? You scored 21 of 25 ( 84% )
Questions 26 - 50 of 100 ? You scored 20 of 25 ( 80% )
Questions 51 - 75 of 100 ? You scored 19 of 25 ( 76% )
Questions 76 - 100 of 100 ? You scored 20 of 25 ( 80% )

Module 2. ? National Electrical Code PART 2
Questions 1- 25 of 100 ? You scored 23 of 25 ( 92% )
Questions 26 - 50 of 100 ? You scored 24 of 25 ( 96% )
Questions 51 - 75 of 100 ? You scored 25 of 25 ( 100% )
Questions 76 - 100 of 100 ? You scored 23 of 25 ( 92% )

Module 3. ? Journeyman Calculations PART 3
Questions 1 - 25 of 65 ? You scored 19 of 25 ( 76% )
Questions 26 - 50 of 65 ? You scored 18 of 25 ( 72% )
Questions 51 - 65 of 65 ? You scored 12 of 15 ( 80% )
There were a few questions I got that I just flat had never heard of before, or did not comprehend the answers provided:
The following information applies to Questions 45-49: Laundry circuit of 1,500 VA; two small-appliance circuits are 3,000 VA; 1/2 hp, 115V motor. Balance these loads on a 115/230V single-phase system, then answer the following question.
The total current of both Line 1 and Line 2 equals _____ amperes.
a. 30-35
b. 36-40
c. 41-45
d. 46-50
Call me crazy, but once these loads are balanced, won't I see roughly 25 amps on each phase, or am I overthinking this? I guessed "D".
Motors with a nameplate temperature rise rating not over 40?C must have the overload protection device sized at no more than _____% of motor nameplate current rating.
a. 100
b. 115
c. 125
d. 135
This one, and similar ones using the term "efficiency factor", completely threw me. I had no idea how to go about answering this question. So, how do you find this answer?

After taking this test, I think I need to spend all the time I can reading 430 front to back and back to front, and make it my best friend. This article truly confuses me to no end. I could probably skate through and pass with a 70%, but I'd rather be comfortable before I get there and do it right.

If anybody wishes to discuss motor philosophy, this is an invitation to do so. :D

Thanks,
 
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Smart $

Esteemed Member
Location
Ohio
I'm with you on the answer to the first question. The way the question is worded, it wouldn't matter whether the loads are balanced or not...

(1500VA + 3000VA)/115V + 9.8A = 48.9A

...and if the desired response is current at 230V, there simply isn't a correct choice. Man, I hate multiple choice questions with no correct answer!!!... Who tests the tester?

On question 2, see 430.32(A)(1)...
 

bphgravity

Senior Member
Location
Florida
Great job on this practice test George! I know you are shooting for a perfect score on the REAL exam, but a pass is a pass. I hope you plan on instructing some day?
 

charlie b

Moderator
Staff member
Location
Lockport, IL
Occupation
Retired Electrical Engineer
The first question is badly worded, and the correct answer does not appear on the list. You were right, George, that the line currents will each be about 25 amps. If you take 9.8 times 115, then add 3000 and add 1500, and finally divide by 230, the line current turns out to be about 24.4 amps.

The problem is with the word "total," in the phrase "total current of both Line 1 and Line 2." The author of that question, like many others who attempt this "simple" calculation, is making the error of thinking that there is such a thing as "total current." They look at 24.4 amps on Line 1, and they look at 24.4 amps on Line 2, and they say, "the total is 24.4 plus 24.4, or 48.8 amps." That is absolutely wrong.

For a perfectly balanced, single phase, 115/230 volt system, at every moment in time the current leaving the source via Line 1 will return to the source via Line 2, and the neutral conductor will carry no current. The mathematical summation of Line 1 current plus Line 2 current is zero, but that "total current" has no significance to the design of electrical distribution systems.
 

George Stolz

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Staff member
Location
Windsor, CO NEC: 2017
Occupation
Service Manager
Thanks for the confirmation on the first question, I thought I was losing my mind. :)

Smart $ said:
On question 2, see 430.32(A)(1)...
Thanks for the reference. In my reading at lunch yesterday, I saw another key word that threw me: ultimate trip current. 430.32(A)(2). I had never seen the term before. I bluffed 125% and didn't have a close answer. :D

Thanks, Bryan: but I better learn motors first. :D :D
 

sparky_magoo

Senior Member
Location
Reno
Cogratulations George! I passed the first two parts of the test ( not quite as well as you), then I chikened out on the rest.
 

George Stolz

Moderator
Staff member
Location
Windsor, CO NEC: 2017
Occupation
Service Manager
Subtract 6% for the comfy green chair and coffee breaks, and I barely passed 70%, guys. Still studying, haven't gotten my registration back yet...

Well, "studying" may be overstating it a bit... :( :)
 
FWIW
I played around with Mike practice exams & thery were tough. Tougher than any others I've had.
George you'll do fine.
I'm not sure about Colorado but Texas Exams only tell you your score, if you fail. Passing only gets you a congratulations and a license.
 

Minuteman

Senior Member
77401 said:
FWIW
Texas Exams only tell you your score, if you fail. Passing only gets you a congratulations and a license.

TeXaS eLeCtRiCaL ExAm:

Question 1) Do you have the exam fee?

Question 2) Do you have it with you?

iF yOu AnSwErEd YeS tO bOtH qUeStIoNs - YoU pAsS!
 
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