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. Some losses occur in all transformers. These losses are classified as copper losses and _____ losses.






2. 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.






3. The output side it develops AC by electromagnetic mutual induction - Secondary voltage is induced in this coil






4. A simple design has a core within each coil






5. The simplest type of transformer core






6. With no load on the secondary winding - a small current flows in the primary called _____ _____.






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






8. Autotransformers are not safe when they supply a _____ voltage from a high voltage source.






9. A large amount of power wasted with the open-ended core






10. A magnet made by winding a coil of wire around a soft iron core. Current passed through this winding produces magnetic lines of force in the coil.






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






12. The relationship between current and voltage in the coils are inverse






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






14. 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.






15. An instrument used to measure electrical current.






16. The current related to turns ratio law






17. A stationary device for transferring alternating current electrical energy from one circuit to another circuit by electromagnetic means.






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






19. It refers to the direction of current flow in a closed circuit.






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






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






22. Used to increase the magnetic flux in a transformer






23. The winding to which voltage is supplied is called the _____ winding.






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






25. The transformer winding to which voltage is supplied is called the _____ winding.






26. The energy is always transferred without a change in frequency - but usually with changes in _____ and _____.






27. The magnetic lines of force that flow from the north pole of a magnet and return to the south pole.






28. Modern; extremely efficient-more effective coupling between primary and secondary coils; smaller and lighter






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






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






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






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






33. What is a rotation meter?






34. Transformers with 4800 volt primaries and 120/240 volt secondaries - either pole or subway type - with two secondary windings terminating at internal links which provide for parallel operation of the secondary windings at 120 volts or series operatio






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






36. Current flows through the primary winding in response to primary voltage and sets up a magnetic field that varies in direction and stregnth. under the influence of the changing magnetic field an AC voltage/kv is induced across the secondary coil by e






37. A ___________ transformer is a continuously adjustable Autotransformer.






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






39. The 3 principle components of a transformer






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






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






42. Transformer losses are classified as _____ and _____.






43. Copper loss is known as _____ loss.






44. The output which can be delivered for the time specified at rated secondary voltage and rated frequency without exceeding the specified temperature limitations.






45. Anything above 600 volts is _____?






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






47. 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.






48. A designated limit of operating characteristics based on definite conditions.






49. The input side that attaches to the AC supply it recieves the electrical energy or incoming voltage






50. In a transformer the _____ current will always flow in such a direction that its magnetizing action will oppose the magnetizing action of the primary winding.