1. A transistor has how many pn junctions? 11. In a pop transistor, the major carriers 20.

ers 20. If the base resistor is open, what is the

a. 1 in the emitter are collector current?
b. 2 a. Free electrons a. 0
c. 3 b. Holes b. 1 mA
d. 4 c. Neither c. 2 mA
d. Both d. 10 mA
2. In an npn transistor, the majority
carriers in the emitter are 12. What is the most important fact about 21. When comparing the power dissipation
a. Free electrons the collector current? of a 2N3904 transistor to the PZT3904
b. Holes a. It is measured in milliamperes. surface-mount version, the 2N3904
c. Neither b. It equals the base current divided by the a. Can handle less power
d. Both current gain. b. Can handle more power
c. It is small. c. Can handle the same power
3. The barrier potential across each silicon d. It approximately equals the emitter current. d. Is not rated
depletion layer is
a. 0 13. If the current gain is 100 and the 22. The current gain of a transistor is
b. 0.3 V collector current is 10 mA, the base current defined as the ratio of the collector current
c. 0.7 V is to the
d. 1V a. 10 µA a. Base current
b. 100 µA b. Emitter current
4. The emitter diode is usually c. 1 A c. Supply current
a. Forward biased d. 10 A d. Collector current
b. Reverse biased
c. Nonconducting 14. The base-emitter voltage is usually 23. The graph of current gain versus
d. Operating in the breakdown region a. Less than the base supply voltage collector current indicates that the current
b. Equal to the base supply voltage gain
5. For normal operation of the transistor, c. More than the base supply voltage a. Is constant
the collector diode has to be d. Cannot answer b. Varies slightly
a. Forward biased c. Varies significantly
b. Reverse biased 15. The collector-emitter voltage is usually d. Equals the collector current divided by the
c. Nonconducting a. Less than the collector supply voltage base current
d. Operating in the breakdown region b. Equal to the collector supply voltage
c. More than the collector supply voltage 24. When the collector current in-creases,
6. The base of an npn transistor is thin and d. Cannot answer what does the current gain do?
a. Heavily doped a. Decreases
b. Lightly doped 16. The power dissipated by a transistor b. Stays the same
c. Metallic approximately equals the collector current c. Increases
d. Doped by a pentavalent material times d. Any of the above
a. Base-emitter voltage
7. Most of the electrons in the base of an b. Collector-emitter voltage 25. As the temperature increases, the
npn transistor flow c. Base supply voltage current gain
a. Out of the base lead d. 0.7 V a. Decreases
b. Into the collector b. Remains the same
c. Into the emitter 17. A transistor acts like a diode and a c. Increases
d. Into the base supply a. Voltage source d. Can be any of the above
b. Current source
8. The beta of a transistor is the ratio of the c. Resistance 26. When the base resistor in-creases, the
a. Collector current to emitter current d. Power supply collector voltage will probably
b. Collector current to base current a. Decrease
c. Base current to collector current 18. In the active region, the collector b. Stay the same
d. Emitter current to collector current current is not changed significantly by c. Increase
a. Base supply voltage d. Do all of the above
9. Increasing the collector supply voltage b. Base current
will increase c. Current gain 27. If the base resistor is very small, the
a. Base current d. Collector resistance transistor will operate in the
b. Collector current a. Cutoff region
c. Emitter current 19. The base-emitter voltage of the second b. Active region
d. None of the above approximation is c. Saturation region
a. 0 d. Breakdown region
10. The fact that there are many free b. 0.3 V
electrons in a transistor emitter region c. 0.7 V 28. Three different Q points are shown on a
means the emitter is d. 1 V load line. The upper Q point represents the
a. Lightly doped a. Minimum current gain
b. Heavily doped b. Intermediate current gain
c. Undoped c. Maximum current gain
d. None of the above d. Cutoff point
 29. If a transistor operates at the middle of 12. With voltage-divider bias, the base
the load line, a decrease in the base 3. If the current gain is unknown in an voltage is
resistance will move the Q point emitter-biased circuit, you cannot calculate a. Less than the base supply voltage
a. Down the b. Equal to the base supply voltage
b. Up a. Emitter voltage C. Greater than the base supply voltage
c. Nowhere b. Emitter current d. Greater than the collector supply voltage
d. Off the load line c. Collector current
d. Base current 13. VDB is noted for its
30. If the base supply voltage is a. Unstable collector voltage
disconnected, the collector-emitter voltage 4. If the emitter resistor is open, the collector b. Varying emitter current
will equal voltage is c. Large base current
a. OV a. Low d. Stable Q point
b. 6 V b. High
c. 10.5 V c. Unchanged 14. With VDB, an increase in collector
d. Collector supply voltage d. Unknown resistance will
a. Decrease the emitter voltage
31. If the base resistor has zero resistance, 5. If the collector resistor is open, the b. Decrease the collector voltage
the transistor will probably be collector voltage is c. Increase the emitter voltage
a. Saturated a. Low d. Decrease the emitter current
b. In cutoff b. High
c. Destroyed c. Unchanged 15. VDB has a stable Q point like
d. None of the above d. Unknown a. Base bias
b. Emitter bias
32. The collector current is 1.5 mA. base 6. When the current gain increases from 50 c. Collector-feedback bias
current gain is 50, the to 300 in an emitter-biased circuit, the d. Emitter-feedback bias
а. 3 µА collector current
b. 30 µА a. Remains almost the same 16. VDB needs
с. 150 µА b. Decreases by a factor of 6 a. Only three resistors
d. 3 mА c. Increases by a factor of 6 b. Only one supply
d. Is zero c. Precision resistors
33. The base current is 50 MA. If the d. More resistors to work better
current gain is 100, the collector current is 7. If the emitter resistance increases, the
closest in value to collector voltage 17. VDB normally operates in the
a. 50 µA a. Decreases a. Active region
b. 500 µA b. Stays the same b. Cutoff region
c. 2 mA c. Increases c. Saturation region
d. 5 mA d. Breaks down the transistor d. Breakdown region

34. When the Q point moves along the load 8. If the emitter resistance decreases, the 18. The collector voltage of a
line, VCE decreases when the collector a. Q point moves up VDB circuit is not sensitive to changes in the
current b. Collector current decreases a. Supply voltage
a. Decreases c. Q point stays where it is b. Emitter resistance
b. Stays the same d. Current gain increase c. Current gain
c. Increases d. Collector resistance
d. Does none of the above 9. The major advantage of a phototransistor
as compared to a photodiode is its 19. If the emitter resistance decreases in a
35. When there is no base current in a a. Response to higher frequencies VDB circuit, the collector voltage
transistor switch, the output voltage from b. AC operation a. Decreases
the transistor is c. Increased sensitivity b. Stays the same
a. Low d. Durability c. Increases
b. High d. Doubles
c. Unchanged 10. For the emitter bias, the voltage across
d. Unknown the emitter resistor is the same as the voltage 20. Base bias is associated with
between the emitter and the a. Amplifiers
a. Base b. Switching circuits
1. A circuit with a fixed emitter current is b. Collector c. Stable Q point
called c. Emitter d. Fixed emitter current
a. Base bias d. Ground
b. Emitter bias 21. If the emitter resistance is reduced by
c. Transistor bias 11. For emitter bias, the voltage at the one-half in a VDB circuit, the collector
d. Two-supply bias emitter is 0.7 V less than the current will
a. Base voltage a. Double
2. The first step in analyzing emitter-based b. Emitter voltage b. Drop in half
circuits is to find the c. Collector voltage c. Remain the same
a. Base current d. Ground voltage d. Increase
b. Emitter voltage
c. Emitter current
d. Collector current
22. If the collector resistance decreases in a 27. If the emitter resistance decreases with 33. Which is the largest current in a pnp
VDB circuit, the collector voltage will TSEB, the collector voltage will transistor?
a. Decrease a. Decrease a. Base current
b. Stay the same b. Stay the same b. Emitter current
c. Increase c. Increase c. Collector current
d. Double d. Equal the collector supply voltage d. None of these

23. The Q point of a VDB circuit is 28. If the base resistor opens with TSEB, the 34. The currents of a pup transistor are
a. Hypersensitive to changes in current gain collector voltage will a. Usually smaller than npn currents
b. Somewhat sensitive to changes in current a. Decrease b. Opposite npn currents
gain b. Stay the same c. Usually larger than npn currents
c. Almost totally insensitive to changes in c. Increase slightly d. Negative
current gain d. Equal the collector supply voltage
d. Greatly affected by temperature changes 35. With pnp voltage-divider bias, you must
29. In TSEB, the base current must be very use
24. The base voltage of two-supply emitter a. Small a. Negative power supplies
bias (TSEB) is b. Large b. Positive power supplies
a. 0.7 V c. Unstable c. Resistors
b. Very large d. Stable d. Grounds
c. Near 0 V 30. The Q point of TSEB does not depend on
d. 1.3 V the 36. With a TSEB pnp circuit using a negative
a. Emitter resistance Vcc supply, the emitter voltage is
25. If the emitter resistance doubles with b. Collector resistance a. Equal to the base voltage
TSEB, the collector current will c. Current gain b. 0.7 V higher than the base voltage
a. Drop in half d. Emitter voltage c. 0.7 V lower than the base voltage
b. Stay the same d. Equal to the collector voltage
c. Double 31. The majority carriers in the emitter of a
d. Increase pnp transistor are 37. In a well-designed VDB circuit, the base
a. Holes current is
26. If a splash of solder shorts the collector b. Free electrons a. Much larger than the voltage divider current
resistor of TSEB, the collector voltage will c. Trivalent atoms b. Equal to the emitter current
a. Drop to zero d. Pentavalent atoms c. Much smaller than the voltage divider current
b. Equal the collector supply voltage d. Equal to the collector current
C. Stay the same 32. The current gain of a pnp transistor is
d. Double a. The negative of the npn current gain 38. In a VDB circuit, the base input
b. The collector current divided by the emitter resistance RIN is
current a. Equal to βdc RE
c. Near zero b. Normally smaller than RTH
d. The ratio of collector current to base current c. Equal to βdc RC
d. Independent of βdc

39. In a TSEB circuit, the base voltage is

approximately zero when
a. The base resistor is very large
b. The transistor is saturated
c. βdc c is very small
d. RB < 0.01 βdc RE