Floyd: MCQ in Bipolar Junction Transistor Amplifiers

This is the Multiple Choice Questions in Bipolar Junction Transistor Amplifiers from the book Electronic Devices – Electron Flow Version and Conventional Current Version 8th Edition by Thomas L. Floyd. If you are looking for a reviewer in Electronics Engineering this will definitely help. I can assure you that this will be a great help in reviewing the book in preparation for your Board Exam. Make sure to familiarize each and every questions to increase the chance of passing the ECE Board Exam.

Online Questions and Answers Topic Outline

• MCQ in BJT Amplifiers
• MCQ in Amplifier Operation
• MCQ in Transistor AC Models
• MCQ in The Common-Emitter Amplifier
• MCQ in The The Common-Collector Amplifier
• MCQ in The The Common-Base Amplifier
• MCQ in Multistage Amplifiers
• MCQ in The Differential Amplifier
• MCQ in GreenTech Application 6: Wind Power

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Practice Exam Test Questions

Choose the letter of the best answer in each questions.

1. For the common-emitter amplifier ac equivalent circuit, all capacitors are

A) effectively shorts.

B) effectively open circuits.

C) not connected to ground.

D) connected to ground.

2. For a common-emitter amplifier, the purpose of the emitter bypass capacitor is

A) no purpose, since it is shorted out by RE.

B) to reduce noise.

C) to despike the supply voltage.

D) to maximize amplifier gain.

3. For a common-emitter amplifier, the purpose of swamping is

A) to minimize gain.

B) to reduce the effects of r’e

C) to maximize gain.

D) no purpose.

4. An emitter-follower is also known as a

A) common-emitter amplifier.

B) common-base amplifier.

C) common-collector amplifier.

D) Darlington pair.

5. In a common-base amplifier, the input signal is connected to the

A) base.

B) collector.

C) emitter.

D) output.

6. The differential amplifier produces outputs that are

A) common mode.

B) in-phase with the input voltages.

C) the sum of the two input voltages.

D) the difference of the two input voltages.

7. The differential amplifier has

A) one input and one output.

B) two inputs and two outputs.

C) two inputs and one output.

D) one input and two outputs.

8. The dc emitter current of a transistor is 8 mA. What is the value of re?

A) 320 Ω

B) 13.3 kΩ

C) 3.125 Ω

D) 5.75 Ω

9. Refer to Figure 6-1. Calculate the value of VB.

Figure 6-1

A) 5 V

B) 3.7 V

C) 20 V

D) 3 V

10. Refer to Figure 6-1. Find the value of IE.

A) 2 mA

B) 4 mA

C) 5 mA

D) 6 mA

11. Refer to Figure 6-1. Determine the value of VC.

A) 20 V

B) 10 V

C) 5 V

D) 0 V

12. Refer to Figure 6-1. Find the value of Rin(base).

A) 420 Ω

B) 50 kΩ

C) 940 Ω

D) 100.8 Ω

13. Refer to Figure 6-1. Calculate the value of Rin_(tot).

A) 37.7 kΩ

B) 3.77 kΩ

C) 378 Ω

D) 2.25 kΩ

14. Refer to Figure 6-1. Determine the value of Av.

A) 49.6

B) 5

C) 100

D) 595

15. Refer to Figure 6-1. If an emitter bypass capacitor was installed, determine the value of Rin(base).

A) 416 Ω

B) 5 kΩ

C) 50 kΩ

D) 500 Ω

16. Refer to Figure 6-1. If an emitter bypass capacitor was installed, calculate the value of Rin(tot).

A) 378 Ω

B) 420 Ω

C) 500 Ω

D) 40 k Ω

17. Refer to Figure 6-1. If an emitter bypass capacitor was installed, what would the new Av be?

A) 4.96

B) 125

C) 398

D) 600

18. An emitter-follower amplifier has an input impedance of 107 kΩ. The input signal is 12 mV. The approximate output voltage is (common-collector)

A) 8.92 V

B) 112 mV

C) 12 mV

D) 8.9 mV

19. Refer to Figure 6-2. You notice while servicing this amplifier that the output signal at Vout is reduced from normal. The problem could be caused by

Figure 6-2

A) an open C3.

B) an open C2.

C) an open base-emitter of Q2.

D) a shorted C2.

20. Refer to Figure 6-2. The output signal from the first stage of this amplifier is 0 V. The trouble could be caused by

A) an open C4.

B) an open C2.

C) an open base-emitter of Q1.

D) a shorted C4.

21. A Darlington pair amplifier has

A) high input impedance and high voltage gain.

B) low input impedance and low voltage gain.

C) a voltage gain of about 1 and a low input impedance.

D) a low voltage gain and a high input impedance.

22. You have a need to apply an amplifier with a very high power gain. Which of the following would you choose?

A) common-collector

B) common-base

C) common-emitter

D) emitter-follower

23. What is the most important r parameter for amplifier analysis?

A) rb′

B) rc′

C) re′

D) none of the above

24. A common-emitter amplifier has _____ voltage gain, _____ current gain, _____ power gain, and _____ input impedance.

A) high, low, high, low

B) high, high, high, low

C) high, high, high, high

D) low, low, low, high

25. To analyze the common-emitter amplifier, what must be done to determine the dc equivalent circuit?

A) leave circuit unchanged

B) replace coupling and bypass capacitors with opens

C) replace coupling and bypass capacitors with shorts

D) replace VCC with ground

26. When the bypass capacitor is removed from a common-emitter amplifier, the voltage gain

A) increases.

B) decreases.

C) has very little effect.

D) none of the above

27. A common-collector amplifier has ______ input resistance, ______ current gain, and ______ voltage gain.

A) high, high, low

B) high, low, low

C) high, low, high

28. A Darlington pair provides beta ______ for ______ input resistance.

A) multiplication, decreased

B) multiplication, increased

C) division, decreased

D) none of the above

29. The total gain of a multistage amplifier is the ______.

A) sum of individual voltage gains

B) sum of dB voltage gains

C) product of individual voltage gains

D) none of the above

30. What is re equal to in terms of h parameters?

A) hre/hoe

B) (hre + 1)/hoe

C) hie – (hre/hoe)(1 + hfe)

D) hfe

E) none of the above

31. The advantage that a Sziklai pair has over a Darlington pair is

A) higher current gain.

B) less input voltage is needed to turn it on.

C) higher input impedance.

D) higher voltage gain.

Check your work.

Complete List of Chapter Quiz in Floyd’s Electronic Devices