Test your basic knowledge |

Subjects : science, engineering
Instructions:
  • Answer 50 questions in 15 minutes.
  • If you are not ready to take this test, you can study here.
  • Match each statement with the correct term.
  • Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.
1. Current that changes periodically in direction is...






2. A control power transformer...






3. The standard frequency of power supplied by the power company is...






4. Two 10-hp induction motors are operating on 460 volts AC. One motor is connected by single- phase; the other is connected in three-phase. The three-phase will...






5. AC voltage is raised or lowered by means of...






6. At what rate should mouth-to-mouth resuscitation be applied?






7. What type motor is a wound-rotor induction motor?






8. If the conductors of a balanced - three-phase circuit pass through a current transformer - how many amps will flow in the transformer?






9. The size of a transformer is measured in...






10. A 3-phase - 2 speed - constant torque motor is running at fast speed. The motor windings are connected wye for fast speed. Motor leads T4 - T5 and T6 are connected to the line leads. Motor leads T1 - T2 and T3 should be...






11. High voltage is used to transmit power over long distances...






12. What value of voltage will be measured from phase-to-phase - in a wye-connected secondary - if 2 -300 volts is measured from phase-to-ground?






13. Find the turns ratio of a single-phase transformer with the following values: Primary power of 5KW - secondary current of 100 amps - and primary voltage of 250 volts.






14. A transformer with a 1:1 ratio is usually a (an)...






15. Define alternating current...






16. Three-phase AC underground cables must be provided with overcurrent protection using a...






17. When connecting 3 single-phase transformers into a three-phase system - which of the following is NOT required for the single-phase transformers.






18. If 13 -200 volts are measured from phase-to-phase across a wye-connected secondary - What is the phase-to-ground voltage?






19. The combined capacitance of two capacitors in parallel is...






20. If you use a clamp-on ammeter or tong tester around all three-phase wires of an energized three- phase circuit simultaneously...






21. Not true about AC power?






22. 460 volts AC is required to operate two motors - one connected in single-phase and the other connected in three-phase. The three-phase motor will...






23. The following motor leads are brought out of a 3-phase motor (T1 - T2 - T3 - T4 - T5 - T6). This motor is probably for...






24. How can you tell if a victim receiving mouth-to-mouth resuscitation is getting air into the lungs?






25. A burn causing a blister is classified as a...






26. What should the duty rating of a grounding resistor be?






27. Should a ground fault occur - what device can be installed to limit the current in the neutral of a three-phase AC system?






28. Under fault conditions - the grounding resistor in a high voltage circuit limits the voltage drop in the grounding circuit external to the resistor to not more than...






29. What is a capacitor?






30. The purpose of a zig-zag transformer is to...






31. Why is 440-volt - three-phase power more commonly used in mining than 220-volt - three-phase power?






32. Not a symptom of electrical shock?.






33. If a voltmeter were placed between two phase leads of a three-phase 480-volt system - the meter would read...






34. Using a 10:1 ratio transformer - the terminals on the secondary side or lower voltage side would be marked...






35. Current transformers - or CT's - are used to...






36. When not connected to a load - the secondary leads of a current transformer should be...






37. What position of a selector switch using a voltmeter would you select to check a 120-volt AC circuit to obtain the most accurate reading?






38. If 2000 watts is read in the primary of a single-phase transformer - What is the wattage in the secondary? (Assuming no losses.)






39. The current on the primary side of a step-down transformer with a 4:1 ratio will be...






40. What steps up or steps down AC voltage?






41. How should clothing be removed from a burn?






42. Compared to the secondary of a loaded - step-down transformer - the primary has...






43. The most reliable method to use to determine whether or not the heart has stopped is by checking the...


44. A transformer with 3000 turns in the primary winding has a primary voltage of 4 -800 volts and a secondary voltage of 240 volts. How many turns are in the secondary winding?






45. A transformer with 10 turns on the primary coil and 100 turns on the secondary is classified as...






46. The property of an electrical circuit that opposes any change in voltage is called...






47. If current were flowing through a grounding resistor in a 440-volt - resistance-grounded system - this would probably be because...






48. A wound-rotor induction motor has all the following EXCEPT...






49. A transformer with 1 -500 turns in the primary winding has a primary voltage of 2 -400 volts and a secondary voltage of 120 volts. How many turns are in the secondary winding?






50. A solenoid coil is...