Neta 3 Exam pointers and questions

[Zepold72]

Does anybody have any pointers to take the Neta # 3 exam. I get anxious when I take tests. i failed it once and I want to pass it this time> i have been taking a lot of quizzes and I do okay(PASS) but somehow I dont feel to confident. I dont have a lot of experience with relays.

[lester mcmanaway]

took my 3 today, the formula sheet is slightly different if you've taken it in the past. the phase sequence formulas were not on the sheet.

Id guess 60% or more questions were relay and metering. unfortunately I missed passing by 2 questions. Id also guess maybe 30% of the questions i've seen listed here.

One questions that comes to mind was something like " a given circuit is 120 vac and has a draw of 10 amps phase is at 10 degrees with 45 magnitude what is the kvar? "i believe these were the choices"

a. 750
b. 1155
c. 1200
d. 77.5

Not sure how to solve this you may see something similar.

[Kimbo Slice]

took my 3 today, the formula sheet is slightly different if you've taken it in the past. the phase sequence formulas were not on the sheet. Id guess 60% or more questions were relay and metering. unfortunately I missed passing by 2 questions. Id also guess maybe 30% of the questions i've seen listed here. 1 that comes to mind was something like " a given circuit is 120 vac and has a draw of 10 amps phase is at 10 degrees with 45 magnitude what is the kvar?
"i believe these were the choices"
a. 750
b. 1155
c. 1200
d. 77.5
Not sure how to solve this you may see something similar.

Was this your first time taking the Neta 3? If not did the questions change a lot? Sorry that you didn't pass.

[lester mcmanaway]

1st attempt at the 3. its been over a year since i took the 2. The format of the test is pretty similar i was expecting it to be way different reading some of the stuff here but it wasn't to bad. i just took another practice test for giggles and there are a lot of questions i seen on the 3 that i have yet to see here. if you have access to the neta quiz's that are published in the magazine there was quite a few of them on the test.

[Zepold72]

took my 3 today, the formula sheet is slightly different if you've taken it in the past. the phase sequence formulas were not on the sheet. Id guess 60% or more questions were relay and metering. unfortunately I missed passing by 2 questions. Id also guess maybe 30% of the questions i've seen listed here. 1 that comes to mind was something like " a given circuit is 120 vac and has a draw of 10 amps phase is at 10 degrees with 45 magnitude what is the kvar?
"i believe these were the choices"
a. 750
b. 1155
c. 1200
d. 77.5
Not sure how to solve this you may see something similar.
Q=V x I x SinΦ?

[Zepold72]

but still dont get any of those choices??

[Zepold72]

how do i inplement the magnitude in this?

[cjones09]

a given circuit is 120 vac and has a draw of 10 amps phase is at 10 degrees with 45 magnitude what is the kvar?
a. 750
b. 1155
c. 1200
d. 77.5
Not sure how to solve this you may see something similar.

Also not sure how to solve this, somehow need to find real power first. Where does the 45 magnitude come in?

Can anyone help provide a solution?

[rsimmons]

Also not sure how to solve this, somehow need to find real power first. Where does the 45 magnitude come in?

Can anyone help provide a solution?

V = 45 mag, 10 degrees
V phasor notation = 45*cosine(10degrees) - 45*sine(10degrees)*imaginary number
V phasor notation = 44.3 - 7.8*imaginary number
44.3 = real voltage
7.8 = reactive voltage
kvar = reactive voltage * amps
kvar = 7.8*10amps
kvar = 78
78 is close to 77.5

See if that works

[lester mcmanaway]

i have no idea, i tried figuring it out for about 20 minutes during the test and gave up. was hoping someone else here could shed some light. good luck tomorrow. a good portion of the questions i did see that were familiar to here were reworded ever so slightly it will trip you up.

[Zepold72]

Also not sure how to solve this, somehow need to find real power first. Where does the 45 magnitude come in?

Can anyone help provide a solution?

Q=VxI Sin ɸ

Polar coordinates(r,θ) -----------------> Rectangular Coordinates ( r Sin θ, r Cos θ)
θ=10º ( 45 Sin 10º, 45 Cos 10º ) ===> ( 7.814167995, 44.31634889 )
r=45 ( x , y ) ===> ( x , y )
Tan θ = y/x
θ= Tan^-1 (y/x) = Tan ^-1 (44.31634889 / 7.814167995) = 80º

plug in all values

Q = 120 x 10 x Sin 80º = 1181.769304 VAR.

Even though none of the answers match i think this is the right answer.!!

[rsimmons]

Q=VxI Sin ɸ

Polar coordinates(r,θ) -----------------> Rectangular Coordinates ( r Sin θ, r Cos θ)
θ=10º ( 45 Sin 10º, 45 Cos 10º ) ===> ( 7.814167995, 44.31634889 )
r=45 ( x , y ) ===> ( x , y )
Tan θ = y/x
θ= Tan^-1 (y/x) = Tan ^-1 (44.31634889 / 7.814167995) = 80º

plug in all values

Q = 120 x 10 x Sin 80º = 1181.769304 VAR.

Even though none of the answers match i think this is the right answer.!!

The number you calculated is KVA not KVAR. Use the pyragorean theorem. Kva^2 = kw^2 + kvar^2. The mag*sine (theta) ×amps is the kvar = reactive power and not the apparent power in which you calculated. ( Those who read this, look up the power triangle and decide for yourselves)

[Zepold72]

Thanks rsimmons!! I realized it after I posted that I solved for the wrong power.
:cool:

[lester mcmanaway]

so did you pass??