| 1. | The energy gap in a semiconductor ? | |
|
Increases with temperature
|
||
|
Does not change with temperature
|
||
|
Decreases with temperature
|
||
|
Is zero
|
||
View Answer
Discuss in Forum
Report Question| 2. | In an intrinsic Semiconductor the free electron concentration depends on ? | |
|
Effective mass of electrons only
|
||
|
Effective mass of holes only
|
||
|
Temperature of the Semiconductor
|
||
|
Width of the forbidden energy hand of the semiconductor
|
||
| 3. | Direct band gap semiconductors ? | |
|
Exhibit short carrier life time and they are used for fabricating BJT’s
|
||
|
Exhibit long carrier life time and they are used for fabricating BJT’s
|
||
|
Exhibit short carrier life time and they are used for fabricating Lasers
|
||
|
Exhibit long carrier life time and they are used for fabricating BJT’s
|
||
| 4. | According to the Einstein relation, for any semiconductor the ratio of diffusion constant to mobility of carriers ? | |
|
Depends upon the temperature of the semiconductor
|
||
|
Depends upon the type of the semiconductor
|
||
|
Varies with life time of the semiconductor
|
||
|
Is a universal constant
|
||
| 5. | Impurities like boron, aluminum, gallium or indium are added to intrinsic semiconductor to form ? | |
|
N-type doped semiconductor
|
||
|
P-type doped semiconductor
|
||
|
A junction diode
|
||
|
All of these
|
||
| 6. | In a N-type semiconductor, the position of Fermi-level ? | |
|
Is lower than the centre of energy gap
|
||
|
Is at the centre of energy gap
|
||
|
Is higher than the centre of energy gap
|
||
|
Can be any where
|
||
| 7. | The pentavalent impurities like antimony, arsenic, bismuth and phosphorus, added to intrinsic semiconductors are called ? | |
|
Acceptor or P-type impurities
|
||
|
Donor or P-type impurities
|
||
|
Acceptor or N-type impurities
|
||
|
Donor or N-type impurities
|
||
| 8. | For silicon, the energy gap at 300 K is ? | |
|
1.1 W
|
||
|
1.1 J
|
||
|
1.1 Ev
|
||
|
None of these
|
||
| 9. | The arrow direction in the diode symbol indicates ? | |
|
Direction of electron flow
|
||
|
Direction of hole flow (Direction of conventional current)
|
||
|
Opposite to the direction of hole flow
|
||
|
None of the above
|
||
| 10. | The knee voltage (cut in voltage) of Si diode is ? | |
|
0.2 V
|
||
|
0.7 V
|
||
|
0.8 V
|
||
|
1.0 V
|
||