MCQs in Transistor Bias Circuits

This is the Multiple Choice Questions in Transistor Bias Circuits 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

• MCQs in Transistor Bias Circuits
• MCQs in The DC Operating Point
• MCQs in Voltage-Divider Bias
• MCQs in Other Bias Methods
• MCQs in GreenTech Application 5: Wind Power

Practice Exam Test Questions

Choose the letter of the best answer in each questions.

1. Voltage-divider bias has a relatively stable Q-point, as does

• A) base bias.
• B) collector-feedback bias.
• C) both of the above
• D) none of the above

2. Emitter bias requires

• A) only a positive supply voltage.
• B) only a negative supply voltage.
• C) no supply voltage.
• D) both positive and negative supply voltages.

3. Clipping is the result of

• A) the input signal being too large.
• B) the transistor being driven into saturation.
• C) the transistor being driven into cutoff.
• D) all of the above

4. Changes in β_DC result in changes in

• A) I_C.
• B) VC_E.
• C) the Q-point.
• D) all of the above

5. The input resistance at the base of a voltage-divider biased transistor can be neglected

• A) at all times.
• B) only if the base current is much smaller than the current through R2 (the lower bias resistor).
• C) at no time.
• D) only if the base current is much larger than the current through R₂ (the lower bias resistor).

6. What is the Q-point for a fixed-bias transistor with I_B = 75 µA, β_DC = 100, V_CC = 20 V, and R_C = 1.5 kΩ?

• A) V_C = 0 V
• B) V_C = 20 V
• C) V_C = 8.75 V
• D) V_C = 11.25 V

7. Ideally, for linear operation, a transistor should be biased so that the Q-point is

• A) near saturation.
• B) near cutoff.
• C) where I_C is maximum.
• D) halfway between cutoff and saturation.

8. Refer to Figure 5-1. The value of I_B is

Figure 5-1

• A) 53 µA.
• B) 50 µA.
• C) 50 mA.
• D) 53 mA.

9. Refer to Figure 5-1. The value of I_C is

• A) 10 µA.
• B) 10 mA.
• C) 5 mA.
• D) 50 mA.

10. Refer to Figure 5-1. The value of β_DC is

• A) 5.3.
• B) 53.
• C) 94.
• D) 100.

11. Refer to Figure 5-2. Determine I_C.

Figure 5-2

• A) 5 µA
• B) 5 mA
• C) 0 mA
• D) 10 mA

12. Refer to Figure 5-2. Assume that I_C ≈ I_E. Find V_E.

• A) 5 V
• B) 10 V
• C) 15 V
• D) 2.5 V

13. Refer to Figure 5-2. Assume I_C ≈ I_E. Determine the value of R_C that will allow V_CE to equal 10 V.

• A) 1 kΩ
• B) 1.5 kΩ
• C) 2 kΩ
• D) 2.5 kΩ

14. Refer to Figure 5-2. Calculate the current I₂.

• A) 32 mA
• B) 3.2 mA
• C) 168 µA
• D) 320 µA

15. Refer to Figure 5-3(a). The most probable cause of trouble, if any, from these voltage measurements would be

Figure 5-3

• A) the base-emitter junction is open.
• B) R_E is open.
• C) a short from collector to emitter.
• D) no problems.

16. Refer to Figure 5-3(b). The most probable cause of trouble, if any, from these voltage measurements is

• A) the base-emitter junction is open.
• B) RE is open.
• C) a short from collector to emitter.
• D) no problems.

17. Refer to Figure 5-3(c). The most probable cause of trouble, if any, from these voltage measurements is

• A) the base-emitter junction is open.
• B) R_E is open.
• C) a short from collector to emitter.
• D) no problems.

18. Refer to Figure 5-3(d). The most probable cause of trouble, if any, from these voltage measurements is

• A) the base-emitter junction is open.
• B) R_E is open.
• C) a short from collector to emitter.
• D) no problems.

19. The most stable biasing technique used is the

• A) voltage-divider bias.
• B) base bias.
• C) emitter bias.
• D) collector bias.

20. At saturation the value of V_CE is nearly _____, and I_C = _____.

• A) zero, zero
• B) V_CC, I_C(sat)
• C) zero, I_(sat)
• D) V_CC, zero

21. The linear (active) operating region of a transistor lies along the load line below _____ and above _____.

• A) cutoff, saturation
• B) saturation, cutoff

22. What is the most common bias circuit?

• A) base
• B) collector
• C) emitter
• D) voltage-divider

23. What is the dc input resistance at the base of a BJT?

• A) β_DCR_C
• B) βdc • (R_C || R_E)
• C) β_DC • r_e′
• D) β_DCR_E

24. Which transistor bias circuit provides good Q-point stability with a single-polarity supply voltage?

• A) base bias
• B) collector-feedback bias
• C) voltage-divider bias
• D) emitter bias

25. Which transistor bias circuit arrangement has poor stability because its Q-point varies widely with β_DC?

• A) base bias
• B) collector-feedback bias
• C) voltage-divider bias
• D) emitter bias

26. Which transistor bias circuit arrangement provides good Q-point stability, but requires both positive and negative supply voltages?

• A) base bias
• B) collector-feedback bias
• C) voltage-divider bias
• D) emitter bias

27. Which transistor bias circuit arrangement provides good stability using negative feedback from collector to base?

• A) base bias
• B) collector-feedback bias
• C) voltage-divider bias
• D) emitter bias

28.

FIGURE 5-4

Refer to Figure 5-4. In the voltage-divider biased npn transistor circuit, if R_C opens, the transistor is

• A) saturated.
• B) cutoff.
• C) nonconducting.

29. Refer to Figure 5-4. In the voltage-divider biased npn transistor circuit, if R₂ opens, the transistor is

• A) saturated.
• B) cutoff.
• C) nonconducting.

30. Refer to Figure 5-4. In the voltage-divider biased npn transistor circuit, if R₁ opens, the transistor is

• A) saturated.
• B) cutoff.
• C) nonconducting.

Check your work.

Answer in Transistor Bias Circuits

Complete List of Chapter Quiz in Floyd's Electronic Devices

Multiple Choice Questions in Floyd's Electronic Devices

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