 # Floyd: MCQ in Introduction to Semiconductors

(Last Updated On: August 20, 2019)

This is the Multiple Choice Questions in Introduction to Semiconductors 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 Atom
• MCQs in Materials Used in Electronics
• MCQs in Current in Semiconductors
• MCQs in N-Type and P-Type Semiconductors
• MCQs in The PN Junction
• MCQs in GreenTech Application 1: Solar Power

#### Practice Exam Test Questions

Choose the letter of the best answer in each questions.

1. An atom is made up of

A) protons.

B) neutrons.

C) electrons.

D) all of the above

Solution:

2. The maximum number of electrons in each shell of an atom is

A) 2.

B) 2n^2 where n is the number of the shell.

C) 4.

D) 8.

Solution:

3. An n-type semiconductor material

A) is intrinsic.

B) has trivalent impurity atoms added.

C) has pentavalent impurity atoms added.

D) requires no doping.

Solution:

4. A diode conducts when it is forward-biased, and the anode is connected to the __________ through a limiting resistor.

A) positive supply

B) negative supply

C) cathode

D) anode

Solution:

5. The wide end arrow on a schematic indicates the __________ of a diode.

A) ground

B) direction of electron flow

C) cathode

D) anode

Solution:

6. The term bias in electronics usually means

A) the value of ac voltage in the signal.

B) the condition of current through a pn junction.

C) the value of dc voltages for the device to operate properly.

D) the status of the diode.

Solution:

7. Doping of a semiconductor material means

A) that a glue-type substance is added to hold the material together.

B) that impurities are added to increase the resistance of the material.

C) that impurities are added to decrease the resistance of the material.

D) that all impurities are removed to get pure silicon.

Solution:

8. The forward voltage across a conducting silicon diode is about

A) 0.3 V.

B) 1.7 V.

C) –0.7 V.

D) 0.7 V.

Solution:

9. You have an unknown type of diode in a circuit. You measure the voltage across it and find it to be 0.3 V. The diode might be

A) a silicon diode.

B) a germanium diode.

C) a forward-biased silicon diode.

D) a reverse-biased germanium diode.

Solution:

10. A reverse-biased diode has the ______ connected to the positive side of the source, and the ______ connected to the negative side of the source.

A) cathode, anode

B) cathode, base

C) base, anode

D) anode, cathode

Solution:

11. The movement of free electrons in a conductor is called

A) voltage.

B) current.

C) recombination.

D) equilibrium.

Solution:

12. A silicon diode is forward-biased. You measure the voltage to ground from the anode at _____, and the voltage from the cathode to ground at _____.

A) 0 V, 0.3 V

B) 2.3 V, 1.6 V

C) 1.6 V, 2.3 V

D) 0.3 V, 0 V

Solution:

13. There is a small amount of current across the barrier of a reverse-biased diode. This current is called

A) forward-bias current.

B) reverse breakdown current.

C) conventional current.

D) reverse leakage current.

Solution:

14. The boundary between p-type material and n-type material is called

A) a diode.

B) a reverse-biased diode.

C) a pn junction.

D) a forward-biased diode.

Solution:

15. Reverse breakdown is a condition in which a diode

A) is subjected to a large reverse voltage.

B) is reverse-biased and there is a small leakage current.

C) has no current flowing at all.

D) is heated up by large amounts of current in the forward direction.

Solution:

16. As the forward current through a silicon diode increases, the voltage across the diode

A) increases to a 0.7 V maximum.

B) decreases.

C) is relatively constant.

D) decreases and then increases.

Solution:

17. Which statement best describes an insulator?

A) A material with many free electrons.

B) A material doped to have some free electrons.

C) A material with few free electrons.

D) No description fits.

Solution:

18. As the forward current through a silicon diode increases, the internal resistance

A) increases.

B) decreases.

C) remains the same.

D) none of the above

Solution:

19. A silicon diode measures a low value of resistance with the meter leads in both positions. The trouble, if any, is

A) the diode is open.

B) the diode is shorted to ground.

C) the diode is internally shorted.

D) the diode is working correctly.

Solution:

20. Single-element semiconductors are characterized by atoms with ____ valence electrons.

A) 3

B) 4

C) 5

D) 2

Solution:

21. Effectively, how many valence electrons are there in each atom within a silicon crystal?

A) 2

B) 4

C) 8

D) 16

Solution:

22. What occurs when a conduction-band electron loses energy and falls back into a hole in the valence band?

A) doping

B) recombination

C) generation

D) none of the above

Solution:

23. What types of impurity atoms are added to increase the number of conduction-band electrons in intrinsic silicon?

A) bivalent

B) octavalent

C) pentavalent

D) trivalent

E) none of the above

Solution:

24. What factor(s) do(es) the barrier potential of a pn junction depend on?

A) type of semiconductive material

B) the amount of doping

C) the temperature

D) all of the above

Solution:

25. Under normal conditions a diode conducts current when it is

A) reverse-biased.

B) forward-biased.

C) avalanched.

D) saturated.

Solution:

26. For a forward-biased diode, as temperature is _____, the forward current _____ for a given value of forward voltage.

A) decreased, increases

B) increased, increases

C) increased, decreases

D) decreased, decreases

Solution:

27. For a forward-biased diode, the barrier potential _____ as temperature increases.

A) decreases

B) remains constant

C) increases

D) none of the above

Solution:

28. An ideal diode presents a(n) _____ when reversed-biased and a(n) _____ when forward-biased.

A) open, short

B) short, open

C) open, open

D) short, short

Solution:

29. The most common type of diode failure is a(n) _____.

A) open

B) short

C) resistive

D) None of the above

Solution: 