Key Topic 26: Transistors-2

Question 1

3-26C1: A common base amplifier has:

A. More current gain than common emitter or common collector.
B. More voltage gain than common emitter or common collector.
C. More power gain than common emitter or common collector.
D. Highest input impedance of the three amplifier configurations.

Answer 1

B. More voltage gain than common emitter or common collector.

Question 2

3-26C2: What does it mean for a transistor to be cut off?

A. There is no base current.
B. The transistor is at its Class A operating point.
C. There is no current between emitter and collector.
D. There is maximum current between emitter and collector.

Answer 2

C. There is no current between emitter and collector.

Question 3

3-26C3: An emitter-follower amplifier has:

A. More voltage gain than common emitter or common base.
B. More power gain than common emitter or common base.
C. Lowest input impedance of the three amplifier configurations.
D. More current gain than common emitter or common base.

Answer 3

D. More current gain than common emitter or common base.

Question 4

3-26C4: What conditions exists when a transistor is operating in saturation?

A. The base-emitter junction and collector-base junction are both forward biased.
B. The base-emitter junction and collector-base junction are both reversed biased.
C. The base-emitter junction is reverse biased and the collector-base junction is forward biased.
D. The base-emitter junction is forward biased and the collector-base junction is reverse biased.

Answer 4

A. The base-emitter junction and collector-base junction are both forward biased.

Question 5

3-26C5: For current to flow in an NPN silicon transistor’s emitter-collector junction, the base must be:

A. At least 0.4 volts positive with respect to the emitter.
B. At a negative voltage with respect to the emitter.
C. At least 0.7 volts positive with respect to the emitter.
D. At least 0.7 volts negative with respect to the emitter.

Answer 5

C. At least 0.7 volts positive with respect to the emitter.

Question 6

3-26C6: When an NPN transistor is operating as a Class A amplifier, the base-emitter junction:

A. And collector-base junction are both forward biased.
B. And collector-base junction are both reverse biased.
C. Is reverse biased and the collector-base junction is forward biased.
D. Is forward biased and the collector-base junction is reverse biased.

Answer 6

D. Is forward biased and the collector-base junction is reverse biased.