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






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






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






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






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






6. A control power transformer...






7. 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...






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






9. 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?






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






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






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






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






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






15. The transformer used only to measure voltage is a...






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






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






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






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






20. What steps up or steps down AC voltage?






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






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






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






24. Define alternating current...






25. Not a symptom of electrical shock?.






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






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






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






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






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






31. A solenoid coil is...






32. The load to which the secondary winding of a current transformer was connected has opened. The secondary leads should be...






33. Not true about AC power?






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






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






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






37. What is the danger when working around capacitors?






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






39. Which of the following is not needed when using an ohmmeter to determine if a motor is grounded?






40. Surface transformer installations - unless constructed to eliminate shock hazards - must be installed at least...






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






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






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






44. Where should grounding resistors be located?






45. The neutral ground-bed electrical power system of an underground mine should be separated from the lightning arrestor grounds by at least...






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






47. What happens to a motor that is connected to a three-phase cable when two of the cable's leads are reversed?






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






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






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