# electrical

 Resistance of copper? 12.9 ohms Resistance of Aluminum? 21.2 ohms 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)) In a 230/460v dual-rated motor is what voltage when field windings are connected in series? Parellel? series-460vparallel-230v Voltage drop permitted for -Branch circuit? -Entire system? -Feeders? branch- 3%system- 5%feeders- 3% order of conducters best to worst? silver 105%copper 100%gold 72%aluminum 61% Difference between -Kilowatt (Kw) -Kilovolt-ampere (Kva) Kw = 1000 wattsindicates the measure of power available for work, indicates real powerKva = 1000wattsindicates the measure of apparent powerkv=kva when power factor is 1 single phase standard transformer ratings in kva? 11.52.03.05.07.510152537.55075100125Underlined =  also standard 3 phase def. branch circuit The circuit conductors between the final overcurrent device protecting the circuit and the outlets power supplies wired in -parallel? -series? parallel- Voltage remains the same, current (amp hour for batteries) increasesseries- Voltage is added together, current remains the same Volumes allowence per conductor size? 18, 16, 14, 12, 10, 8, 6 18- 1.5              in^316- 1.7514- 2.0012- 2.2510- 2.58- 3.006- 5.00 one horsepower = ____watts 746 watts When doing a feeder service calculation the load demand factor is? 100% for the first 3kva35% 3001va-120,000 va25% 120,001va and up values of AC? Instantaneous value- value at any given moment ranging from peak to neg peakPeak value- effective value /.707                  - effective value x 1.414Effective value- is DC voltage equivalent AKA RMS "root mean squared" backwards Volatge drop formula? VD = (2 x K x D x I)/cm Voltage drop = 2 x constant x distance x currant / Circular mills Resister colors? Bad beer rots our young guts but vodka goes wellblack brown red orange yellow green blue violet gray white risister values? 1st band - first number2nd band- 2nd number3rd band- multiplie4th band- tolarance 5%-10% 5th band- quality AuthorAnonymous ID173757 Card Setelectrical Descriptionfor journeyman test Updated2012-09-27T02:19:25Z Show Answers