MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 657 Mcqs, each offering curated multiple-choice questions to sharpen your Testing Subject knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
The P - type semiconductor impurities are also called as |
| A. | Acceptor impurities |
| B. | Donor impurities |
| C. | Either (a) or (b) |
| D. | None of these |
| Answer» B. Donor impurities | |
| 2. |
The cut - in voltage for silicon and germanium are |
| A. | 0.3 V, 0.3 V |
| B. | 0.3 V, 0.7 V |
| C. | 0.7 V, 0.7 V |
| D. | 0.7 V, 0.3 V |
| Answer» E. | |
| 3. |
Filters are used to convert |
| A. | Pulsating dc signal into a pure dc signal |
| B. | Pure dc signal into a pulsating dc signal |
| C. | Pulsating dc signal into a pure ac signal |
| D. | Pulsating ac signal into a pure dc signal |
| Answer» B. Pure dc signal into a pulsating dc signal | |
| 4. |
When the graph between current through and voltage across a device is a straight line, the device is referred to as ………………. |
| A. | linear |
| B. | active |
| C. | nonlinear |
| D. | passive |
| Answer» B. active | |
| 5. |
The knee voltage of a crystal diode is approximately equal to …………. |
| A. | applied voltage |
| B. | breakdown voltage |
| C. | forward voltage |
| D. | barrier potential |
| Answer» E. | |
| 6. |
If the doping level of a crystal diode is increased, the breakdown voltage…………. |
| A. | remains the same |
| B. | is increased |
| C. | is decreased |
| D. | none of the above |
| Answer» D. none of the above | |
| 7. |
The PIV rating of a crystal diode is ………….. that of equivalent vacuum diode |
| A. | the same as |
| B. | lower than |
| C. | more than |
| D. | none of the above |
| Answer» C. more than | |
| 8. |
If the temperature of a crystal diode increases, then leakage current ……….. |
| A. | remains the same |
| B. | decreases |
| C. | increases |
| D. | becomes zero |
| Answer» D. becomes zero | |
| 9. |
The leakage current in a crystal diode is due to ……………. |
| A. | minority carriers |
| B. | majority carriers |
| C. | junction capacitance |
| D. | none of the above |
| Answer» B. majority carriers | |
| 10. |
An ideal crystal diode is one which behaves as a perfect ……….. when forward biased. |
| A. | conductor |
| B. | insulator |
| C. | resistance material |
| D. | none of the above |
| Answer» B. insulator | |
| 11. |
The d.c. resistance of a crystal diode is ………….. its a.c. resistance |
| A. | the same as |
| B. | more than |
| C. | less than |
| D. | none of the above |
| Answer» D. none of the above | |
| 12. |
A crystal diode is used as …………… |
| A. | an amplifier |
| B. | a rectifier |
| C. | an oscillator |
| D. | a voltage regulator |
| Answer» C. an oscillator | |
| 13. |
The forward voltage drop across a silicon diode is about ………………… |
| A. | 2.5 V |
| B. | 3 V |
| C. | 10 V |
| D. | 0.7 V |
| Answer» E. | |
| 14. |
The reverse current in a diode is of the order of ………………. |
| A. | kA |
| B. | mA |
| C. | μA |
| D. | A |
| Answer» D. A | |
| 15. |
If the arrow of crystal diode symbol is positive w.r.t. bar, then diode is ………….. biased. |
| A. | forward |
| B. | reverse |
| C. | either forward or reverse |
| D. | none of the above |
| Answer» B. reverse | |
| 16. |
A crystal diode has forward resistance of the order of …………… |
| A. | kΩ |
| B. | Ω |
| C. | MΩ |
| D. | none of the above |
| Answer» C. MΩ | |
| 17. |
A crystal diode has ……… |
| A. | one pn junction |
| B. | two pn junctions |
| C. | three pn junctions |
| D. | none of the above |
| Answer» B. two pn junctions | |
| 18. |
At room temperature, an intrinsic silicon crystal acts approximately as …… |
| A. | A battery |
| B. | A conductor |
| C. | An insulator |
| D. | A piece of copper wire |
| Answer» D. A piece of copper wire | |
| 19. |
At absolute temperature, an intrinsic semiconductor has ………. |
| A. | A few free electrons |
| B. | Many holes |
| C. | Many free electrons |
| D. | No holes or free electrons |
| Answer» E. | |
| 20. |
At room temperature, an intrinsic semiconductor has ………. |
| A. | Many holes only |
| B. | A few free electrons and holes |
| C. | Many free electrons only |
| D. | No holes or free electrons |
| Answer» C. Many free electrons only | |
| 21. |
In an intrinsic semiconductor, the number of free electrons ……… |
| A. | Equals the number of holes |
| B. | Is greater than the number of holes |
| C. | Is less than the number of holes |
| D. | None of the above |
| Answer» B. Is greater than the number of holes | |
| 22. |
The leakage current in a pn junction is of the order of |
| A. | Aa |
| B. | mA |
| C. | kA |
| D. | µA |
| Answer» E. | |
| 23. |
With forward bias to a pn junction , the width of depletion layer ……… |
| A. | Decreases |
| B. | Increases |
| C. | Remains the same |
| D. | None of the above |
| Answer» B. Increases | |
| 24. |
When the temperature of an extrinsic semiconductor is increased, the pronounced effect is on…… |
| A. | Junction capacitance |
| B. | Minority carriers |
| C. | Majority carriers |
| D. | None of the above |
| Answer» C. Majority carriers | |
| 25. |
The leakage current across a pn junction is due to ………….. |
| A. | Minority carriers |
| B. | Majority carriers |
| C. | Junction capacitance |
| D. | None of the above |
| Answer» B. Majority carriers | |
| 26. |
A reverse biased pn junction has resistance of the order of |
| A. | Ω |
| B. | kΩ |
| C. | MΩ |
| D. | None of the above |
| Answer» D. None of the above | |
| 27. |
A pn junction acts as a ………. |
| A. | Controlled switch |
| B. | Bidirectional switch |
| C. | Unidirectional switch |
| D. | None of the above |
| Answer» D. None of the above | |
| 28. |
A reverse bias pn junction has ………… |
| A. | Very narrow depletion layer |
| B. | Almost no current |
| C. | Very low resistance |
| D. | Large current flow |
| Answer» C. Very low resistance | |
| 29. |
In the depletion region of a pn junction, there is a shortage of …….. |
| A. | Acceptor ions |
| B. | Holes and electrons |
| C. | Donor ions |
| D. | None of the above |
| Answer» C. Donor ions | |
| 30. |
The barrier voltage at a pn junction for germanium is about ……… |
| A. | 5 V |
| B. | 3 V |
| C. | Zero |
| D. | 3 V |
| Answer» E. | |
| 31. |
The battery connections required to forward bias a pn junction are …… |
| A. | +ve terminal to p and –ve terminal to n |
| B. | -ve terminal to p and +ve terminal to n |
| C. | -ve terminal to p and –ve terminal to n |
| D. | None of the above |
| Answer» B. -ve terminal to p and +ve terminal to n | |
| 32. |
The random motion of holes and free electrons due to thermal agitation is called ………. |
| A. | Diffusion |
| B. | Pressure |
| C. | Ionisation |
| D. | None of the above |
| Answer» B. Pressure | |
| 33. |
In a semiconductor, current conduction is due to …….. |
| A. | Only holes |
| B. | Only free electrons |
| C. | Holes and free electrons |
| D. | None of the above |
| Answer» D. None of the above | |
| 34. |
A hole and electron in close proximity would tend to ………. |
| A. | Repel each other |
| B. | Attract each other |
| C. | Have no effect on each other |
| D. | None of the above |
| Answer» C. Have no effect on each other | |
| 35. |
As the doping to a pure semiconductor increases, the bulk resistance of the semiconductor ……….. |
| A. | Remains the same |
| B. | Increases |
| C. | Decreases |
| D. | None of the above |
| Answer» D. None of the above | |
| 36. |
The impurity level in an extrinsic semiconductor is about ….. of pure semiconductor. |
| A. | 10 atoms for 108 atoms |
| B. | 1 atom for 108 atoms |
| C. | 1 atom for 104 atoms |
| D. | 1 atom for 100 atoms |
| Answer» C. 1 atom for 104 atoms | |
| 37. |
A hole in a semiconductor is defined as ……………. |
| A. | A free electron |
| B. | The incomplete part of an electron pair bond |
| C. | A free proton |
| D. | A free neutron |
| Answer» C. A free proton | |
| 38. |
Addition of trivalent impurity to a semiconductor creates many …….. |
| A. | Holes |
| B. | Free electrons |
| C. | Valence electrons |
| D. | Bound electrons |
| Answer» B. Free electrons | |
| 39. |
A trivalent impurity has ….. valence electrons |
| A. | 4 |
| B. | 5 |
| C. | 6 |
| D. | 3 |
| Answer» E. | |
| 40. |
A pentavalent impurity has ………. Valence electrons |
| A. | 3 |
| B. | 5 |
| C. | 4 |
| D. | 6 |
| Answer» C. 4 | |
| 41. |
Addition of pentavalent impurity to a semiconductor creates many …….. |
| A. | Free electrons |
| B. | Holes |
| C. | Valence electrons |
| D. | Bound electrons |
| Answer» B. Holes | |
| 42. |
When a pentavalent impurity is added to a pure semiconductor, it becomes ……… |
| A. | An insulator |
| B. | An intrinsic semiconductor |
| C. | p-type semiconductor |
| D. | n-type semiconductor |
| Answer» E. | |
| 43. |
The strength of a semiconductor crystal comes from …….. |
| A. | Forces between nuclei |
| B. | Forces between protons |
| C. | Electron-pair bonds |
| D. | None of the above |
| Answer» D. None of the above | |
| 44. |
When a pure semiconductor is heated, its resistance ………….. |
| A. | Goes up |
| B. | Goes down |
| C. | Remains the same |
| D. | Can’t say |
| Answer» C. Remains the same | |
| 45. |
A semiconductor has generally ……………… valence electrons. |
| A. | 2 |
| B. | 3 |
| C. | 6 |
| D. | 4 |
| Answer» E. | |
| 46. |
The most commonly used semiconductor is ……….. |
| A. | Germanium |
| B. | Silicon |
| C. | Carbon |
| D. | Sulphur |
| Answer» C. Carbon | |
| 47. |
A semiconductor has ………… temperature coefficient of resistance. |
| A. | Positive |
| B. | Zero |
| C. | Negative |
| D. | None of the above |
| Answer» D. None of the above | |
| 48. |
A semiconductor is formed by ……… bonds. |
| A. | Covalent |
| B. | Electrovalent |
| C. | Co-ordinate |
| D. | None of the above |
| Answer» B. Electrovalent | |