MCQs in Bipolar Junction Transistors

This is the Multiple Choice Questions in Bipolar Junction Transistors 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 Bipolar Junction Transistor (BJT) Structure
• MCQs in Basic BJT Operation
• MCQs in BJT Characteristics and Parameters
• MCQs in The BJT as an Amplifier
• MCQs in The Phototransistor
• MCQs in The BJT as a Switch
• MCQs in Transistor Categories and Packaging
• MCQs in GreenTech Application 4: Solar Power

Practice Exam Test Questions

Choose the letter of the best answer in each questions.

1. The dc load line on a family of collector characteristic curves of a transistor shows the

• A) saturation region.
• B) cutoff region.
• C) active region.
• D) all of the above

2. A transistor data sheet usually identifies β_DC as

• A) h_re.
• B) h_fe.
• C) I_C.
• D) V_CE.

3. When a transistor is used as a switch, it is stable in which two distinct regions?

• A) saturation and active
• B) active and cutoff
• C) saturation and cutoff
• D) none of the above

4. For a silicon transistor, when a base-emitter junction is forward-biased, it has a nominal voltage drop of

• A) 0.7 V.
• B) 0.3 V.
• C) 0.2 V.
• D) V_CC.

5. The value of β_DC

• A) is fixed for any particular transistor.
• B) varies with temperature.
• C) varies with I_C.
• D) varies with temperature and I_C.

6. The term BJT is short for

• A) base junction transistor.
• B) binary junction transistor.
• C) both junction transistor.
• D) bipolar junction transistor.

7. A BJT has an I_B of 50 µA and a βDC of 75; I_C is:

• A) 375 mA
• B) 37.5 mA
• C) 3.75 mA
• D) 0.375 mA

8. A certain transistor has I_C = 15 mA and I_B = 167 µA; β_DC is:

• A) 15
• B) 167
• C) 0.011
• D) 90

9. For normal operation of a pnp BJT, the base must be _____ with respect to the emitter and _____ with respect to the collector.

• A) positive, negative
• B) positive, positive
• C) negative, positive
• D) negative, negative

10. A transistor amplifier has a voltage gain of 100. If the input voltage is 75 mV, the output voltage is:

• A) 1.33 V
• B) 7.5 V
• C) 13.3 V
• D) 15 V

11. A 35 mV signal is applied to the base of a properly biased transistor with an r'_e = 8 Ω and R_C = 1 kΩ. The output signal voltage at the collector is:

• A) 3.5 V
• B) 28.57 V
• C) 4.375 V
• D) 4.375 mV

12. Refer to Figure 4-1; the value of V_BE is:

Figure 4-1

• A) 0.6 V
• B) 0.7 V
• C) 1.2 V
• D) 0.079 V

13. Refer to Figure 4-1; the value of V_CE is:

• A) 9.9 V
• B) 9.2 V
• C) 0.7 V
• D) 19.3 V

14. Refer to Figure 4-1; the value of V_BC is:

• A) 9.2 V
• B) 9.9 V
• C) –9.9 V
• D) –9.2 V

15. Refer to Figure 4-2; if V_CE = 0.2 V, I_C(sat) is:

Figure 4-2

• A) 0.05 mA
• B) 2.085 mA
• C) 1.065 mA
• D) 7.4 mA

16. Refer to Figure 4-2. Determine the minimum value of I_B that will produce saturation.

• A) 0.25 mA
• B) 5.325 A
• C) 1.065 A
• D) 10.425 A

17. Refer to Figure 4-2. Determine the minimum value of V_IN from the following that will saturate this transistor.

• A) 13.21 V
• B) 12.51 V
• C) 0.7 V
• D) 9.4 V

18. Refer to Figure 4-3. The value of β_DC = 100 and V_IN = 8 V. Determine I_C(sat).

Figure 4-3

• A) 18 mA
• B) 7.92 mA
• C) 1.8 mA
• D) 8 A

19. Refer to Figure 4-3. In this circuit β_DC = 100 and V_IN = 8 V. The value of R_B that will produce saturation is:

• A) 92 kΩ
• B) 9.1 MΩ
• C) 100 kΩ
• D) 150 kΩ

20. Refer to Figure 4-3. The measured voltage, V_CE, is 20 V. The transistor is in

• A) saturation.
• B) cutoff.
• C) normal.
• D) not enough data.

21. Refer to Figure 4-3. You measure V_CE and find it nearly equal to zero. You now know that the transistor is

• A) operating in cutoff.
• B) operating normally.
• C) operating in saturation.
• D) operating below cutoff.

22. What is the order of doping, from heavily to lightly doped, for each region?

• A) base, collector, emitter
• B) emitter, collector, base
• C) emitter, base, collector
• D) collector, emitter, base

23. What are the two types of bipolar junction transistors?

• A) npn and pnp
• B) pnn and nnp
• C) ppn and nnp
• D) pts and stp

24. Which of the following is true for an npn or pnp transistor?

• A) I_E = I_B + I_C
• B) I_B = I_C+ I_E
• C) I_C = I_B + I_E
• D) none of the above

25. What is the ratio of I_C to I_B?

• A) β_DC
• B) h_FE
• C) α_DC
• D) either β_DC or h_FE, but not α_DC

26. What is the ratio of I_C to I_E?

• A) β_DC
• B) β_DC / (β_DC + 1)
• C) α_DC
• D) either β_DC / (β_DC + 1) or α_DC, but not β_DC

27. In what range of voltages is the transistor in the linear region of its operation?

• A) 0 < V_CE
• B) 0.7 < V_CE < V_CE(max)
• C) V_CE(max) > V_CE
• D) none of the above

28. What does DC vary with?

• A) I_C
• B) ºC
• C) both I_C and ºC
• D) I_C’, but not ºC

29. What is (are) common fault(s) in a BJT-based circuit?

• A) opens or shorts internal to the transistor
• B) open bias resistor(s)
• C) external opens and shorts on the circuit board
• D) all of the above

30. What is (are) general-purpose/small-signal transistors case type(s)?

• A) TO-18
• B) TO-92
• C) TO-39
• D) TO-52
• E) all of the above

31. The magnitude of dark current in a phototransistor usually falls in what range?

• A) mA
• B) μA
• C) nA
• D) pA

Check your work.

Answer in Bipolar Junction Transistors

Complete List of Chapter Quiz in Floyd's Electronic Devices

Multiple Choice Questions in Floyd's Electronic Devices

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