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. Which of the following does a squirrel cage induction motor have?






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






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






4. A solenoid coil is...






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






6. The property of an electric circuit that opposes any change in current is called...






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






8. The main function of CT's and PT's on a main substation is to...






9. If any two-phase wires are reversed on a three-phase motor - the motor will...






10. How should clothing be removed from a burn?






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






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






13. A transformer has a primary voltage of 2 -400 volts and a secondary reading of 120 volts. If there are 1 -500 turns on the primary - how many turns are on the secondary?






14. What steps up or steps down AC voltage?






15. 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...






16. Not an acceptable method for the installations of surface transformers?






17. 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...






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






19. 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.






20. A transformer has a primary voltage of 2 -800 volts and a secondary reading of 140 volts. If there are 2000 turns on the primary - how many turns are on the secondary?






21. All transformers step voltage up or down by...






22. A current transformer has a ratio of 350:5. If the phase current is 70 amperes - what would be the secondary current?






23. How do you change the direction of a 3-phase AC motor?






24. 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...






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






26. Alternating current may be defined as...






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






28. The standard frequency of alternating current used at a mine is...






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






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






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






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






33. 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?






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






35. A transformer has 1 -600 turns in the primary and 400 turns in the secondary. The primary voltage is 2 -400 volts. What is the secondary voltage?






36. The secondary windings on a 10:1 step-down transformer will have a wire size...






37. When troubleshooting a circuit with a bank of capacitors - what precautions must be taken?






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






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






40. What is a capacitor?






41. Not a symptom of electrical shock?.






42. What is the first step to be followed in aiding a victim of electrical shock?






43. The primary leads of a single-phase transformer should be connected to the...






44. Operating coils - motors - transformers - relays and solenoids depend upon...






45. To protect against over-current in a three-phase circuit over-current protection must be provided for...






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






47. Where should grounding resistors be located?






48. 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...






49. The speed of an alternating current - squirrel-cage induction motor is...






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