# ELECTRICAL ENGINEERING

1) The reason that NOR logic POS networks are redrawn, as in Figure 5-4, is:

A) to minimize the number of parts required

B) to make it easier to determine the logical output

C) that it shows the actual gate arrangement

D) to help make the transition to a K-map

Figure 5-5

2) Figure 5-5: Which figure above represents typical AND-OR logic implementation?

A) Figure A B) Figure B C) Figure C D) Figure D

ELN-133 Chapter 5 Homework Spring 2015 Combinational Logic

AB Tech Page 2 of 17 McCormick

Figure 5-6

3) Which of the choices in Figure 5-6 is equivalent to the Reference Circuit above?

A) Figure (A) B) Figure (B) C) Figure (C) D) Figure (D)

Figure 5-7

4) Figure 5-7: Which of these choices is equivalent to the Reference Circuit?

A) Figure A B) Figure B C) Figure C D) Figure D

ELN-133 Chapter 5 Homework Spring 2015 Combinational Logic

AB Tech Page 3 of 17 McCormick

Refer to the figure below to answer the following question(s).

Figure 5-8

5) Which of the following logic expressions represents the logic diagram in Figure 5-8?

A) 𝑿 = 𝑨 ∙ 𝑩̅̅̅̅ + �̅� ∙ 𝑩 B) 𝑿 = 𝑨 ∙ 𝑩 + 𝑨 ∙ 𝑩

C) 𝑿 = 𝑨 ∙ 𝑩̅̅ ̅̅ ̅̅ + �̅� ∙ �̅� D) 𝑿 = �̅� ∙ �̅� + 𝑨 ∙ 𝑩

6) What type of logic circuit is represented by Figure 5-8?

A) XOR B) XNOR C) XAND D) XNAND

ELN-133 Chapter 5 Homework Spring 2015 Combinational Logic

AB Tech Page 4 of 17 McCormick

Refer to the figure below to answer the following question(s).

Figure 5-9

7) A correct logic expression for Figure 5-9 is:

A) 𝑿 = �̅�𝑩𝑪 + 𝑨�̅�𝑫 B) 𝑿 = (�̅�𝑩)(𝑨�̅�𝑪𝑫) C) (�̅�𝑩)(𝑨𝑪 + �̅�𝑫) D) (𝑨𝑩�̅�)(�̅�𝑩𝑫)

8) The simplest output equation for Figure 5-9 is:

A) 𝑿 = �̅�𝑩�̅�𝑫 B) 𝑿 = �̅�(𝑩�̅� + 𝑪𝑫) C) 𝑿 = 𝑨�̅�𝑪 + 𝑩�̅�𝑫 D) 𝑿 = �̅�(𝑩𝑪𝑫)

ELN-133 Chapter 5 Homework Spring 2015 Combinational Logic

AB Tech Page 5 of 17 McCormick

Questions 9 and 10 relate to the equation: 𝑿 = 𝑨𝑪�̅� + �̅�𝑩(𝑪𝑫 + 𝑩𝑪)

9) How many gates, including inverters, are required to implement the equation before

simplification? Draw out your implementation. You may use gates with MORE than one input!

Answer for # 9 A) 5 B) 9 C) 7 D) 3

ELN-133 Chapter 5 Homework Spring 2015 Combinational Logic

AB Tech Page 6 of 17 McCormick

10) How many gates, including inverters, are required to implement the equation, after

simplification with Boolean algebra? Write out your derivation of the equation and draw your

implementation. You may use gates with MORE than one input!

Answer for #10 A) 5 B) 9 C) 7 D) 3

ELN-133 Chapter 5 Homework Spring 2015 Combinational Logic

AB Tech Page 7 of 17 McCormick

11) The NAND gate is referred to as a “universal” gate, because it:

A) can be found in almost all digital circuits

B) can be used to build all the other types of gates

C) is grown in all the counties of NC

D) was the first gate to be integrated

Figure 5-10

12) Which of the circuits in Figure 5-10 is the sum-of-products implementation of the Reference

Circuit?

A) Figure(A) B) Figure (B) C) Figure (C) D) Figure (D)

ELN-133 Chapter 5 Homework Spring 2015 Combinational Logic

AB Tech Page 8 of 17 McCormick

Refer to the figure below to answer the following question(s).

Figure 5-11

13) Which of the figures in Figure 5-11 represents the NAND implementation of a NOR gate?

A) Figure A B) Figure B C) Figure C D) Figure D

14) Which of the figures in Figure 5-11 represents the NAND implementation of an OR gate?

A) Figure (A) B) Figure (B) C) Figure (C) D) Figure (D)

15) Which of the figures in Figure 5 -11 represents the NAND implementation of an INVERTER gate?

A) Figure (A) B) Figure (B) C) Figure (C) D) Figure (D)

16) The relationship between a NAND gate and a negative-OR gate is expressed by:

A) 𝑨𝑩̅̅ ̅̅ = �̅� + �̅� B) �̅� + �̅� = 𝑨 + 𝑩̅̅ ̅̅ ̅̅ ̅̅ C) 𝑨𝑩 = 𝑨 + 𝑩̅̅ ̅̅ ̅̅ ̅̅ D) 𝑨𝑩 = �̿� + �̿�

ELN-133 Chapter 5 Homework Spring 2015 Combinational Logic

AB Tech Page 9 of 17 McCormick

Figure 5-12

17) The logical equivalent of the Reference Circuit in Figure 5-12 is:

A) Figure (A) B) Figure (B) C) Figure (C) D) Figure (D)

18) When the inverted output of one gate is connected to the inverted input of another gate:

A) the inversions cancel B) a double inversion occurs and the signal is inverted

C) one inversion cancels the other and only a single inversion results

D) All of the above are correct.

ELN-133 Chapter 5 Homework Spring 2015 Combinational Logic

AB Tech Page 10 of 17 McCormick