Transformer

Couldn't confirm presence of Flash 7 or higher because JavaScript was disabled.Get FlashI really do have Flash installed.ul{margin-top:0px;margin-bottom:0px;list-style-type:none;padding-left:20px;}All the question's and answer's in this Quiz are found in Tom Henry's book, "Transformer Exam Calculations".1. What is the short circuit current most dependant on at the service?

[ ] a. Overcurrent protection

[ ] b. Size of the transformer

[ ] c. Method of grounding

[ ] d. Method of bonding

2. In the AC circuit when the power factor is unity, the reactive power is _______?

[ ] a. at maximum

[ ] b. a negative quanity

[ ] c. equal to I 2 R

[ ] d. zero

3. If the full rating of a transformer is 90 kw at 90% power factor, the kva rating would be ________?

[ ] a. 100

[ ] b. 90

[ ] c. 81

[ ] d. 64

4. What is the turns ratio of a 480/208/120v three phase transformer?

[ ] a. 480/208

[ ] b. 2/1

[ ] c. 4/1

[ ] d. 1/2

5. How much current does a 12kw load take from a 230 volt single phase system 88% power factor?

[ ] a. 52.17 amp

[ ] b. 45.9 amp

[ ] c. 59.28 amp

[ ] d. 65 amp

6. A voltage transformer has turns ration of 5/1. The wire on the _______ is larger?

[ ] a. primary

[ ] b. secondary

[ ] c. tertiary

[ ] d. windings are the same

7. What is the efficiency of a single phase transformer that has an input of 92 amps on 240 volts with an output of 20kw?

[ ] a. 98%

[ ] b. .905

[ ] c. 62%

[ ] d. 94%

8. The kva input is most nearly ______ if the load of the transformer is 500 watt?

[ ] a. 1500

[ ] b. 500

[ ] c. .5

[ ] d. 50

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