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






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






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






4. The primary function of a power transformer is to provide...






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






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






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






8. Find the turns ratio of a single-phase transformer with the following values: Primary power of 10 KW - secondary current of 200 amps - and primary voltage of 250 volts.






9. 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.






10. What type of 3-phase AC motor is used most often around a mine?






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






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






13. If a voltmeter is connected between a phase lead and the ground of a three-phase 480-volt system - the meter will read...






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






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






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






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


18. A transformer has 2000 turns in the primary and 500 turns in the secondary. The primary voltage is 3 -200 volts. What is the secondary voltage?






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






20. Current that changes periodically in direction is...






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






22. 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...






23. What is a capacitor?






24. Not true about AC power?






25. How should clothing be removed from a burn?






26. 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?






27. 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...






28. Define alternating current...






29. 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?






30. What is the danger when working around capacitors?






31. 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...






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






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






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






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






36. Not a symptom of electrical shock?.






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






38. 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?






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






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






41. What steps up or steps down AC voltage?






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






43. 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...






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






45. The minimum allowable size for trailing cables for mobile haulage equipment powered by alternating current is...






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






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






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






49. Where should grounding resistors be located?






50. A solenoid coil is...