# electrical

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1. Resistance of copper?
12.9 ohms
2. Resistance of Aluminum?
21.2 ohms
3. Neutral load of a 3-wire feeder supplied by a 4-wire 3-phase 120/208v or 277/480v wye-connected system formula.
Ln= root of ((L1^2 + L2^2) - (L1 x L2))
4. In a 230/460v dual-rated motor is what voltage when field windings are connected in series?
Parellel?
• series-460v
• parallel-230v
5. Voltage drop permitted for
-Branch circuit?
-Entire system?
-Feeders?
• branch- 3%
• system- 5%
• feeders- 3%
6. order of conducters best to worst?
• silver 105%
• copper 100%
• gold 72%
• aluminum 61%
7. Difference between
-Kilowatt (Kw)
-Kilovolt-ampere (Kva)
• Kw = 1000 watts
• indicates the measure of power available for work, indicates real power
• Kva = 1000watts
• indicates the measure of apparent power
• kv=kva when power factor is 1
8. single phase standard transformer ratings in kva?
• 1
• 1.5
• 2.0
• 3.0
• 5.0
• 7.5
• 10
• 15
• 25
• 37.5
• 50
• 75
• 100
• 125
• Underlined =  also standard 3 phase
9. def. branch circuit
The circuit conductors between the final overcurrent device protecting the circuit and the outlets
10. power supplies wired in
-parallel?
-series?
• parallel- Voltage remains the same, current (amp hour for batteries) increases
• series- Voltage is added together, current remains the same
11. Volumes allowence per conductor size?
18, 16, 14, 12, 10, 8, 6
• 18- 1.5              in^3
• 16- 1.75
• 14- 2.00
• 12- 2.25
• 10- 2.5
• 8- 3.00
• 6- 5.00
12. one horsepower = ____watts
746 watts
13. When doing a feeder service calculation the load demand factor is?
• 100% for the first 3kva
• 35% 3001va-120,000 va
• 25% 120,001va and up
14. values of AC?
• Instantaneous value- value at any given moment ranging from peak to neg peak
• Peak value- effective value /.707
•                   - effective value x 1.414
• Effective value- is DC voltage equivalent
•  AKA RMS "root mean squared" backwards
15. Volatge drop formula?
VD = (2 x K x D x I)/cm

Voltage drop = 2 x constant x distance x currant / Circular mills
16. Resister colors?
• Bad beer rots our young guts but vodka goes well
• black brown red orange yellow green blue violet gray white
17. risister values?
• 1st band - first number
• 2nd band- 2nd number
• 3rd band- multiplie
• 4th band- tolarance 5%-10%
• 5th band- quality

### Card Set Information

 Author: Anonymous ID: 173757 Filename: electrical Updated: 2012-09-27 02:19:25 Tags: electrical Folders: Description: for journeyman test Show Answers:

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