A P-N-P transistor is used in common-emitter mode in an amplifier circuit. A change of 60 in the base brings a change of 5 mA in collector current and 0.05V in base emitter voltage. If a load resistance of 7 k is used, then what would be the voltage gain of the amplifier?
500
600
700
800
The ratio of change in collector current to the change in input base-emitter voltage is know as
A.C. voltage gain
Transconductance
Power gain
D.C. current gain
At what temperature, there are no electrons in the conduction band of semi-conductors and the valence band is completely foiled?
0 K
0 oC
300 K
300 oC
Addition of p-type impurity of an intrinsic semi-conductor results in
Increase in concentration of free electrons above the intrinsic value
Decrease in the number of holes below the intrinsic value
Decrease in concentration of free electrons below the intrinsic value
Increase in the number of holes above the intrinsic value
In which of the following phenomena, the energy required for the emission of electrons from the metal surface is being supplied by thermal energy?
Photoelectric emission
Field emission
Secondary emission
None of the above
Zener breakdown occurs in junctions which,
Being heavily doped, have wide depletion layers
Being lightly doped, have narrow depletion layers
Being lightly doped, have wide depletion layers
Being heavily doped, have narrow depletion layers
/
A given transistor has a current gain If it is connected in a grounded base configuration, what theoretical a.c. collector current will flow when an a.c. current of 3 mA flows through the emitter (Assume the collector potential to be constant)?
2.96 mA
3.76 mA
4.32 mA
3.12 mA
In a transistor circuit, collector load is 8 K whereas quiescent current (Zero single collector current) is 2 mA. If Vcc = 20 V, then what would be the operating point?
8 V, 5 mA
7 V, 4 mA
6 V, 3 mA
4 V, 2 mA
At what temperature it is observed that semiconductors have resistivity lying between metals and insulators?
27o C
20o C
100o C
0o C