

MCQOPTIONS
This section includes 35 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering Questions knowledge and support exam preparation. Choose a topic below to get started.
1. |
The most commonly used semiconductor is________________? |
A. | Germanium |
B. | Silicon |
C. | Carbon |
D. | Sulphur |
Answer» C. Carbon | |
2. |
The barrier voltage at a pn junction for germanium is about________________? |
A. | 5 V |
B. | 3 V |
C. | Zero |
D. | 0.3 V |
Answer» E. | |
3. |
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. | |
4. |
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 | |
5. |
A reverse biased pn junction has resistance of the order of________________? |
A. | O |
B. | kO |
C. | MO |
D. | None of the above |
Answer» D. None of the above | |
6. |
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 | |
7. |
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 | |
8. |
The leakage current in a pn junction is of the order of________________? |
A. | Aa |
B. | mA |
C. | kA |
D. | µA |
Answer» E. | |
9. |
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 | |
10. |
A forward biased pn junction diode has a resistance of the order of_____________? |
A. | O |
B. | kO |
C. | MO |
D. | None of the above |
Answer» B. kO | |
11. |
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 | |
12. |
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 | |
13. |
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 | |
14. |
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 | |
15. |
The resistivity of pure germanium under standard conditions is about_______________? |
A. | 6 x 104 cm |
B. | 60 x cm |
C. | 3 x 106 cm |
D. | 6 x 10-4 cm |
Answer» C. 3 x 106 cm | |
16. |
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 | |
17. |
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 | |
18. |
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 | |
19. |
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 | |
20. |
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 | |
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. |
Addition of trivalent impurity to a semiconductor creates many_______________? |
A. | Holes |
B. | Free electrons |
C. | Valence electrons |
D. | Bound electrons |
Answer» B. Free electrons | |
23. |
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 | |
24. |
Addition of pentavalent impurity to a semiconductor creates many________________? |
A. | Free electrons |
B. | Holes |
C. | Valence electrons |
D. | Bound electrons |
Answer» B. Holes | |
25. |
A pentavalent impurity has______________Valence electrons? |
A. | 3 |
B. | 5 |
C. | 4 |
D. | 6 |
Answer» C. 4 | |
26. |
A semiconductor has ______________ temperature coefficient of resistance? |
A. | Positive |
B. | Zero |
C. | Negative |
D. | None of the above |
Answer» D. None of the above | |
27. |
A semiconductor has generally_______________valence electrons? |
A. | 2 |
B. | 3 |
C. | 6 |
D. | 4 |
Answer» E. | |
28. |
An n-type semiconductor is______________? |
A. | Positively charged |
B. | Negatively charged |
C. | Electrically neutral |
D. | None of the above |
Answer» D. None of the above | |
29. |
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 | |
30. |
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 | |
31. |
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. | |
32. |
A trivalent impurity has______________valence electrons? |
A. | 4 |
B. | 5 |
C. | 6 |
D. | 3 |
Answer» E. | |
33. |
A semiconductor is formed by ______________bonds? |
A. | Covalent |
B. | Electrovalent |
C. | Co-ordinate |
D. | None of the above |
Answer» B. Electrovalent | |
34. |
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 | |
35. |
The resistivity of a pure silicon is about _______________? |
A. | 100 O cm |
B. | 6000 O cm |
C. | 3 x 105 O m |
D. | 6 x 10-8 O cm |
Answer» C. 3 x 105 O m | |