#### speakeelsy PE

##### Well-known member

yeah pencil and paper was only $350... though we're supposed to get a $25 refund if we sign up before January...not sure that's a great consolation prize for getting jerked around for a year, but whatever!WOW! CBT is expensive $375 + tax.

A is definitely incorrect. zero sequence currents and voltages are equal in magnitude and angles. If C is incorrect, then A is incorrect. it shouldn't matter if they are currents or voltages.@Tim @ NCEES I believe there is a typo in the sample. Referring to question 12:

Question:

View attachment 18349

Answer given in the book:

View attachment 18350

Symmetrical Component section from the reference handbook:

View attachment 18351

I believe the answer should be (B, D), excluding (A). Option A states "The three zero-sequence current phasors are equal in magnitude and displaced by 120°." The solution states "Options (A) and (B) are correct, by definition from the transformation matrices shown in the [reference handbook]." However, if we look at the section in the reference handbook, we can clearly see that the zero-sequence current phasors (even though only voltage phasors are specified) haveno displacement. Option A would only be true if it said "The three zero-sequence current phasors are equal in magnitude andare in phase." Or "The three zero-sequence current phasors are equal in magnitude and displaced by0°" It would also be true if it said "The threepositive-sequence current phasors are equal in magnitude and displaced by 120°."

However, I have been wrong before. If anyone notices that I missed something please let me know.

Frustrating!!!