MCQOPTIONS
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MCQOPTIONS
This section includes 47 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
An SCR is turned off when ___________ |
| A. | Anode current is reduced to zero |
| B. | Gate voltage is reduced to zero |
| C. | Gate is reverse biased |
| D. | None of the above |
| Answer» B. Gate voltage is reduced to zero | |
| 2. |
In an SCR circuit the supply voltage is generally ___________ that of breakover voltage |
| A. | Equal to |
| B. | Less than |
| C. | Greater than |
| D. | None of the above |
| Answer» C. Greater than | |
| 3. |
We can control a.c. power in a load by connecting ___________ |
| A. | Two SCRs in series |
| B. | Two SCRs in parallel |
| C. | Two SCRs in parallel opposition |
| D. | None of the above |
| Answer» D. None of the above | |
| 4. |
An SCR is made of silicon and not germanium because silicon |
| A. | Is inexpensive |
| B. | Is mechanically strong |
| C. | Has small leakage current |
| D. | Is tetravalent |
| Answer» D. Is tetravalent | |
| 5. |
An SCR combines the features of ___________ |
| A. | A rectifier and resistance |
| B. | A rectifier and transistor |
| C. | A rectifier and capacitor |
| D. | None of the above |
| Answer» C. A rectifier and capacitor | |
| 6. |
An SCR has ___________ semiconductor layers |
| A. | Two |
| B. | Three |
| C. | Four |
| D. | None of the above |
| Answer» D. None of the above | |
| 7. |
An SCR is sometimes called ___________ |
| A. | Triac |
| B. | Diac |
| C. | Unijunction transistor |
| D. | Thyristor |
| Answer» E. | |
| 8. |
When SCR is OFF, the current in the circuit is ___________ |
| A. | Exactly zero |
| B. | Small leakage current |
| C. | Large leakage current |
| D. | None of the above |
| Answer» C. Large leakage current | |
| 9. |
The control element of an SCR is ___________ |
| A. | Cathode |
| B. | Anode |
| C. | Anode supply |
| D. | Gate |
| Answer» E. | |
| 10. |
When an SCR is turned on, the voltage across it is about ___________ |
| A. | Zero |
| B. | 10 V |
| C. | 1.5 V |
| D. | 1 V |
| Answer» E. | |
| 11. |
If firing angle in an SCR circuit is increased, the output ___________ |
| A. | Remains the same |
| B. | Is increased |
| C. | Is decreased |
| D. | None of the above |
| Answer» D. None of the above | |
| 12. |
An SCR is turned off by ___________ |
| A. | Reducing anode voltage to zero |
| B. | Reducing gate voltage to zero |
| C. | Reverse biasing the gate |
| D. | None of the above |
| Answer» B. Reducing gate voltage to zero | |
| 13. |
The normal way to turn on a SCR is by ___________ |
| A. | Appropriate anode current |
| B. | Appropriate gate current |
| C. | None of the above |
| D. | |
| Answer» D. | |
| 14. |
In an SCR circuit, the angle of conduction can be changed by ___________ |
| A. | Changing anode voltage |
| B. | Changing gate voltage |
| C. | Reverse biasing the gate |
| D. | None of the above |
| Answer» C. Reverse biasing the gate | |
| 15. |
An SCR is a solid state equivalent of ___________ |
| A. | Triode |
| B. | Pentode |
| C. | Gas-filled triode |
| D. | Tetrode |
| Answer» D. Tetrode | |
| 16. |
An SCR behaves as a ___________ switch |
| A. | Unidirectional |
| B. | Bidirectional |
| C. | Mechanical |
| D. | None of the above |
| Answer» B. Bidirectional | |
| 17. |
In normal operation of an SCR, gate is ___________w.r.t. cathode |
| A. | Positive |
| B. | Negative |
| C. | At zero potential |
| D. | None of the above |
| Answer» B. Negative | |
| 18. |
In the normal operation of an SCR, anode is ___________ w.r.t. cathode |
| A. | At zero potential |
| B. | Negative |
| C. | Positive |
| D. | None of the above |
| Answer» D. None of the above | |
| 19. |
An SCR can exercise control over ___________ of a.c. supply |
| A. | Positive half-cycles only |
| B. | Negative half-cycles only |
| C. | Both positive and negative half-cycles |
| D. | Positive or negative half-cycles |
| Answer» E. | |
| 20. |
An SCR is a ___________ triggered device |
| A. | Voltage |
| B. | Current |
| C. | Voltage as well as current |
| D. | None of the above |
| Answer» C. Voltage as well as current | |
| 21. |
The control element of an SCR is ___________%! |
| A. | Cathode |
| B. | Anode |
| C. | Anode supply |
| D. | Gate |
| Answer» E. | |
| 22. |
When an SCR is turned on, the voltage across it is about ___________%! |
| A. | Zero |
| B. | 10 V |
| C. | 1.5 V |
| D. | 1 V |
| Answer» E. | |
| 23. |
If firing angle in an SCR circuit is increased, the output ___________%! |
| A. | Remains the same |
| B. | Is increased |
| C. | Is decreased |
| D. | None of the above |
| Answer» D. None of the above | |
| 24. |
An SCR is turned off by ___________%! |
| A. | Reducing anode voltage to zero |
| B. | Reducing gate voltage to zero |
| C. | Reverse biasing the gate |
| D. | None of the above |
| Answer» B. Reducing gate voltage to zero | |
| 25. |
The normal way to turn on a SCR is by ___________%! |
| A. | |
| B. | Appropriate anode current |
| C. | Appropriate gate current |
| Answer» D. | |
| 26. |
In the normal operation of an SCR, anode is ___________ w.r.t. cathode%! |
| A. | At zero potential |
| B. | Negative |
| C. | Positive |
| D. | None of the above |
| Answer» D. None of the above | |
| 27. |
*/*_In an SCR circuit, the angle of conduction can be changed by ___________? |
| A. | Changing anode voltage |
| B. | Changing gate voltage |
| C. | Reverse biasing the gate |
| D. | None of the above |
| Answer» C. Reverse biasing the gate | |
| 28. |
*/*_An SCR is turned off when ___________? |
| A. | Anode current is reduced to zero |
| B. | Gate voltage is reduced to zero |
| C. | Gate is reverse biased |
| D. | None of the above |
| Answer» B. Gate voltage is reduced to zero | |
| 29. |
*/*_An SCR combines the features of ___________? |
| A. | A rectifier and resistance |
| B. | A rectifier and transistor |
| C. | A rectifier and capacitor |
| D. | None of the above |
| Answer» C. A rectifier and capacitor | |
| 30. |
*/*_In the normal operation of an SCR, anode is ___________ w.r.t. cathode? |
| A. | At zero potential |
| B. | Negative |
| C. | Positive |
| D. | None of the above |
| Answer» D. None of the above | |
| 31. |
*/*_An SCR can exercise control over ___________ of a.c. supply? |
| A. | Positive half-cycles only |
| B. | Negative half-cycles only |
| C. | Both positive and negative half-cycles |
| D. | Positive or negative half-cycles |
| Answer» E. | |
| 32. |
_ An SCR is a solid state equivalent of ___________$? |
| A. | Triode |
| B. | Pentode |
| C. | Gas-filled triode |
| D. | Tetrode |
| Answer» D. Tetrode | |
| 33. |
_ In an SCR circuit the supply voltage is generally ___________ that of breakover voltage$? |
| A. | Equal to |
| B. | Less than |
| C. | Greater than |
| D. | None of the above |
| Answer» C. Greater than | |
| 34. |
_ An SCR has ___________ semiconductor layers$? |
| A. | Two |
| B. | Three |
| C. | Four |
| D. | None of the above |
| Answer» D. None of the above | |
| 35. |
_ An SCR can exercise control over ___________ of a.c. supply$? |
| A. | Positive half-cycles only |
| B. | Negative half-cycles only |
| C. | Both positive and negative half-cycles |
| D. | Positive or negative half-cycles |
| Answer» E. | |
| 36. |
_An SCR behaves as a ___________ switch$? |
| A. | Unidirectional |
| B. | Bidirectional |
| C. | Mechanical |
| D. | None of the above |
| Answer» B. Bidirectional | |
| 37. |
_We can control a.c. power in a load by connecting ___________$? |
| A. | Two SCRs in series |
| B. | Two SCRs in parallel |
| C. | Two SCRs in parallel opposition |
| D. | None of the above |
| Answer» D. None of the above | |
| 38. |
_An SCR is sometimes called ___________$? |
| A. | Triac |
| B. | Diac |
| C. | Unijunction transistor |
| D. | Thyristor |
| Answer» E. | |
| 39. |
_An SCR is a ___________ triggered device$? |
| A. | Voltage |
| B. | Current |
| C. | Voltage as well as current |
| D. | None of the above |
| Answer» C. Voltage as well as current | |
| 40. |
In normal operation of an SCR, gate is ___________w.r.t. cathode? |
| A. | Positive |
| B. | Negative |
| C. | At zero potential |
| D. | None of the above |
| Answer» B. Negative | |
| 41. |
An SCR is made of silicon and not germanium because silicon? |
| A. | Is inexpensive |
| B. | Is mechanically strong |
| C. | Has small leakage current |
| D. | Is tetravalent |
| Answer» D. Is tetravalent | |
| 42. |
When SCR is OFF, the current in the circuit is ___________? |
| A. | Exactly zero |
| B. | Small leakage current |
| C. | Large leakage current |
| D. | None of the above |
| Answer» C. Large leakage current | |
| 43. |
When SCR starts conducting, then ___________ loses all control |
| A. | Gate |
| B. | Cathode |
| C. | Anode |
| D. | None of the above |
| Answer» B. Cathode | |
| 44. |
An SCR has ___________ pn junctions |
| A. | Two |
| B. | Three |
| C. | Four |
| D. | None of the above |
| Answer» C. Four | |
| 45. |
An SCR has three terminals viz ___________ |
| A. | Cathode, anode, gate |
| B. | Anode, cathode, grid |
| C. | Anode, cathode, drain |
| D. | None of the above |
| Answer» B. Anode, cathode, grid | |
| 46. |
If gate current is increased, then anode-cathode voltage at which SCR closes ___________ |
| A. | Is decreased |
| B. | Is increased |
| C. | Remains the same |
| D. | None of the above |
| Answer» B. Is increased | |
| 47. |
An SCR is made of ___________ |
| A. | Germanium |
| B. | Silicon |
| C. | Carbon |
| D. | None of the above |
| Answer» C. Carbon | |