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Q1: MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Which logic gate is described by the following truth table?

A 0 0 1 1

B 0 1 0 1

X 1 0 0 0

A) NOR

B) OR

C) AND

D) NAND

Answer: A 2) Waveforms A and B represent the inputs to a NAND gate. During which time interval(s) will the output from the gate (X) be LOW?

A) time intervals 2, 3, and 4 C) time interval 2

B) never D) time intervals 2 and 3

Answer: C 3) Which output is correct for this NOR truth table?

A 0 0 1 1

B 0 1 0 1

X ? ? ? ?

A) 0 0 0 1

B) 0 1 1 1

C) 1 0 0 0

Answer: C

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D) 1 1 1 0


4) Waveforms A and B represent the inputs to a NAND gate. During which time interval(s) will the output from the gate (X) be HIGH?

A) time intervals 1 and 2 C) time intervals 1, 2, 4, and 5

B) time interval 5 D) time interval 3

Answer: C 5) Which logic function can be implemented by connecting an inverter to the output of an OR gate? A) AND B) OR C) NOR D) inverter Answer: C 6) A + 1 = ________. A) 1

B) 0

C) A

D) A

B) 0

C) A

D) A

B) 0

C) A

D) A

B) 0

C) A

D) A

B) 0

C) A

D) A

C) X = A + B

D) X = A + AB

C) X = C + AC

D) X = AC + B

C) X = A B C

D) X = A + B + C

Answer: A 7) A + A = ________. A) 1 Answer: C 8) A ¡ A = ________. A) 1 Answer: B 9) A + A = ________. A) 1 Answer: A 10) A = ________. A) 1 Answer: C 11) The simplest form of X = (A + B)A + AB is ________. A) X = B

B) X = A + B

Answer: A 12) The simplest form of X = AC + C(A + B) is ________. A) X = AC + BC

B) X = A + BC

Answer: B 13) The simplest form of X = (A + B) + AC is ________. A) X = A B

B) X = A + AC

Answer: A 2


14) What is the simplest form of X = A + AC ? A) X = AC

B) X = C

C) X = A + C

D) It is in its simplest form.

Answer: C 15) What is the simplest form of X = AB + AC + BC? A) X = BC + C

B) X = AB + C

C) X = A + BC

D) It is in its simplest form.

Answer: D 16) The simplest form of X = A(B + C) + AB is ________. A) X = AB + AB

B) X = AC + AB

C) X = AC

D) X = B + AC

C) X = AB + AC

D) X = A

C) ABC

D) = A*B*C + A*B*C

Answer: D 17) The simplest form of X = AB + ABC + A(B + C) is ________. A) X = AB + AC + C

B) X = AB + C

Answer: D 18) The simplest form of X = (AB + AC)BC is ________. A) = A*C + B*C B) X = A + B*C Answer: C 19) By using DeMorgan's theorem, X = A(B + C) is simplified to ________. A) X = A + B + C

B) X = ABC

C) X = A + BC

D) X = A(B + C)

Answer: C 20) Which of the following is an example of DeMorgan's theorem? A) AB = A B

B) AB = A + B

C) A B = A + B

D) A + B = A + B

Answer: B 21) Which Boolean expression indicates an inverted gate output? A) A + B

B) A + B

C) A + B

D) A + B

B) A + B

C) A + B

D) AB

B) AB

C) A + B

D) A + B

C) a NOR gate.

D) an inverter.

Answer: A 22) A + AB = ________. A) AB Answer: C 23) A + AB = ________. A) AB Answer: C 24) An AND gate with inverted inputs functions as A) an OR gate. B) a NAND gate. Answer: C

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25) A NAND gate with inverted inputs functions as A) an OR gate. B) a NOR gate.

C) an AND gate.

D) a NAND gate.

C) a NAND gate.

D) an OR gate.

27) A NAND gate with all inputs tied to one signal functions as A) an OR gate. B) a NOR gate. C) an AND gate.

D) an inverter.

Answer: A 26) A NOR gate with inverted inputs functions as A) a NOR gate. B) an AND gate. Answer: B

Answer: D 28) A NAND gate with its output inverted functions as A) an AND gate. B) an inverter.

C) a NOR gate.

D) an OR gate.

C) a NOR gate.

D) an OR gate.

Answer: A 29) A NAND gate with each input inverted functions as A) an AND gate. B) an inverter. Answer: D 30) Which answer is an example of a product-of-sum (POS) expression? A) X = AB + CD B) X = ABC C) X = A + B + C

D) X = (A + B)(C + D)

Answer: D 31) The final output of a product-of-sum (POS) circuit is generated by A) a NOR. B) an OR. C) a NAND.

D) an AND.

Answer: D 32) The final output of a sum-of-products (SOP) circuit is generated by A) a NOR. B) an OR. C) an AND.

D) a NAND.

Answer: B 33) Which answer is an example of a sum-of-products (SOP) expression? A) X = (AB)(CD) B) X = AB + AC C) X = A + B

D) X = (A + B)(C + D)

Answer: B 34) Which Boolean equation expresses the commutative law? A) AB + AC = A(B + C)

B) AB = AB

C) AB = BA

D) A + (B + C) = (A + B) + C

Answer: C 35) A · A = ________. A) 1

B) 0

C) A

D) A

B) 0

C) A

D) A

Answer: C 36) A + 0 = ________. A) 1 Answer: C

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37) Which logic circuit is represented by the Boolean equation A + B + C + D = X? A) OR B) NAND C) Inverter

D) NOR

Answer: D 38) Waveforms A and B represent the inputs to a NAND gate. During which time interval(s) will the output from the gate (X) be HIGH?

A) time interval 5 C) time intervals 1, 2 and 3

B) time interval 4 D) time intervals 4 and 5

Answer: D

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