Test your basic knowledge |

Transformers

Subject : 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 terminals of the high voltage winding are marked _____.






2. A transformer loses less than _% in energy






3. Kind of wire is the secondary coil in a transformer






4. The relationship between amperage flowing through the coils and the number of turns on individual coils is inverse






5. The current related to turns ratio law






6. The 4 types of transformer cores






7. Instrument transformers reduce high voltages and currents to safe - usable values for the operation of _____ _____.






8. _____ shows that the voltages across the windings of a transformer are directly proportional to the turns in each winding.






9. Two coils wound on a closed iron core form a ________.






10. Refers to the transformer's ability to avoid power loss (heat)






11. How the voltage and the number of turns are related for the voltage related to turn ratio






12. This is the most advanced and most efficient type of tansformer; it is commonly used in x-ray equipment






13. closed core with a top and bottom. It directs the magnetic field towards the primary and secondary coils and increases the field stregnth






14. The winding to which the load is connected is called the _____ winding.






15. A part of a circuit made of a low melting point material so that it will melt and break the circuit when a specified current exceeded. Always the weakest point in the circuit.






16. The entire transformer is placed in a metal tank then immersed in ________.






17. The terminals of the low voltage winding are marked _____.






18. A test instrument used to indicate low voltage potentials in the range of 110 to 600 volts either alternating or direct current. (slang term: wiggy)






19. The 3 principle components of a transformer






20. Core losses are _____ loss and _____ - _____ loss.






21. _____ shows that the voltamperes of the primary of a transformer equal the voltamperes of the secondary of a transformer.






22. The formula for the voltage related to turns ratio






23. The simplest type of transformer core






24. This core is more efficient than the air core because the iron core in each coil intensifies the magnetic flux in both primary and secondary coils when they become magnetized as current flows through each set of coils






25. Divergence of the magnetic field causes this






26. Reference to a jumper or conductor - to or from a piece of electrical equipment.






27. How a variable degree of core saturation is accomplished in a saturable reactor?






28. A transformer is a device that has no moving parts and that transfers energy from one circuit to another by _____.






29. A system of conductors in which at least one conductors or point (usually the middle wire or neutral point of a transformer or generator windings) is intentionally grounded either solididly or through a current-limiting device.






30. A ___________ transformer is a continuously adjustable Autotransformer.






31. Waste of power known as transformer loss - often produced by closed-ended core






32. Instrument transformers reduce high voltages and currents to safe - usable values for the operation of _____ equipment.






33. For a step up and step down transformer if the turns ratio is constant this is the only way to change the output voltage






34. The volt-amperes of the primary of a transformer is equal to the _____ - _____ output of the transformer.






35. The total numbre of lines or force issuing from a pole. (north or south)






36. Insulated primary and secondary coils are in close proximity to each other - no iron core and very innefficient






37. An abnormal connection of relative low resistance - whether made accidentally or intentionally - between two point of different potential in a circuit.






38. An electromagnetic device that operates on the principle of self induction. It uses AC.






39. The loss of power required to reverse the core magnatism each time the current reverses. This loss is caused by friction between the molecules of iron as these particles are aligned first in one direction and the in the opposite direct as current dir






40. The winding of a transformer to which electrical energy is supplied.






41. A magnetic field changing with respect to the conductor will generate a _____ in the conductor.






42. A transformer is a device that either increases or decreases alternating current and voltage using this principle






43. The turns ratio between the windings (primary & secondary) of a transformer unless otherwise specified.






44. Defined as the ratio of the power output to the power input (in a closed circuit containing resistance)






45. The current flowing through the primary winding - in response to the applied primary voltage - sets this up






46. When an alternating current is applied to the high-voltage (H) winding of a transformer with no load on the secondary (X) winding - a small current - called the _____ current - flows in the primary.






47. This type of core is moderately efficient due to closing the core and layering design which reduces power loss from less leakage flux which provides a continuous path for magnetic flux and an increase in field strength






48. Copper loss is known as _____ loss.






49. Both the primary and secondary coils in a transformer are arranged around this






50. Function of the dielectric oil