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DigitalElectronicsU1L3CombinationLogic

Multiple Choice
Identify the choice that best completes the statement or answers the question.
 

 1. 
In terms of digital logic, a HIGH voltage usually represents
a.
a zero.
c.
an illegal condition.
b.
an open.
d.
a one.
 

 2. 
In term of digital logic, a one is usually represented by
a.
0 V.
c.
+10 V.
b.
+5 V.
d.
+15 V.
 

 3. 
In terms of digital logic, a LOW voltage usually represents
a.
an illegal condition.
c.
a one.
b.
an open.
d.
a zero.
 

 4. 
In terms of digital logic, a zero is usually represented by
a.
-5 V.
c.
+2 V.
b.
0 V.
d.
-10 V.
 

 5. 
In order to produce a HIGH output, an AND gate requires
a.
any input to be LOW.
c.
all inputs to be HIGH.
b.
any input to be HIGH.
d.
all inputs to be LOW.
 

 6. 
Which logic function is represented by the equation AB = X?
a.
adder
c.
clock
b.
OR
d.
AND
 

 7. 
Which logic function is represented by the equation ABCD = X?
a.
OR
c.
inverter
b.
AND
d.
clock
 

 8. 
The Boolean equation for an AND gate is ________.
a.
A - B = X
c.
A + B = X
b.
AB = X
d.
A/B = X
 

 9. 
The Boolean equation for an OR gate is ________.
a.
A - B = X
c.
A/B = X
b.
A + B = X
d.
AB = X
 

 10. 
In order to produce a LOW output, an OR gate requires
a.
all inputs to be HIGH.
c.
any input to be LOW.
b.
any input to be HIGH.
d.
all inputs to be LOW.
 

 11. 
Which logic function is represented by the equation A + B = X?
a.
AND
c.
OR
b.
clock
d.
switch
 

 12. 
If one input of an OR gate is HIGH while the other is a clock signal, the output is
a.
LOW.
c.
a clock signal.
b.
HIGH.
d.
cannot be determined
 

 13. 
If one input of an AND gate is HIGH while the other is a clock signal, the output is
a.
a clock signal.
c.
HIGH.
b.
LOW.
d.
cannot be determined
 

 14. 
If both inputs of an AND gate are normally HIGH but one of them momentarily dips LOW, the output will
a.
momentarily dip LOW.
c.
stay HIGH.
b.
be LOW.
d.
go LOW and remain LOW.
 

 15. 
If both inputs of an OR gate are normally HIGH but one of them momentarily dips LOW, the output will
a.
stay HIGH.
c.
be LOW.
b.
go LOW and remain LOW.
d.
momentarily dip LOW.
 

 16. 
How many two-input gates are in a single 14-pin DIP integrated circuit?
a.
four
c.
eight
b.
six
d.
two
 

Multiple Response
Identify one or more choices that best complete the statement or answer the question.
 

 17. 

      Using Multisim, enter the Inverter Gate test circuit shown below. Use a switch for the input X and a probe for the output Z. Toggle the switch to complete the truth table shown.

mr017-1.jpg   
X
Z
0
 
1
 

Note: When the switch is at GND, the input is a (0). When it is at +5V, the input is a (1).  Likewise, when the probe is on, the output is a (1). When the probe is off, the output is a (0).  SHOW ME YOUR WORKING CIRCUIT.
Select all the answers that are true for this truth table shown above.
 a.
When X=0, Z=1
 c.
When X=1, Z=1
 b.
When X=0, Z=0
 d.
When X=1, Z=0
 

 18. 

      Using Multisim, enter the AND Gate test circuit shown below. Use switches for the inputs X & Y and a probe for the output Z. Toggle the switches to complete the truth table shown.
mr018-1.jpg
X
Y
Z
0
0
 
0
1
 
1
0
 
1
1
 

Simulating your circuit on Multisim, select ALL of the answers below that are true for the following truth table.
 a.
X=0, Y=0, Z= 0
 e.
X=1, Y=0, Z= 0
 b.
X=0, Y=0, Z= 1
 f.
X=1, Y=0, Z= 1
 c.
X=0, Y=1, Z= 0
 g.
X=1, Y=1, Z= 0
 d.
X=0, Y=1, Z= 1
 h.
X=1, Y=1, Z= 1
 

 19. 

      Using Multisim, enter the OR Gate test circuit shown below. Use switches for the inputs X & Y and a probe for the output Z. Toggle the switches to complete the truth table shown.
                                    mr019-1.jpg
X
Y
Z
0
0
 
0
1
 
1
0
 
1
1
 

Simulating your circuit on Multisim, select ALL of the answers below that are true for the following truth table.
 a.
X=0, Y=0, Z= 0
 e.
X=1, Y=0, Z= 0
 b.
X=0, Y=0, Z= 1
 f.
X=1, Y=0, Z= 1
 c.
X=0, Y=1, Z= 0
 g.
X=1, Y=1, Z= 0
 d.
X=0, Y=1, Z= 1
 h.
X=1, Y=1, Z= 1
 

Problem
 

 20. 

Now it’s time for you to implement your first AOI combinational logic circuit. The circuit that we will use for this purpose is the Car Safety Buzzer design that was first introduced in the presentation associated with this activity. The design specifications for this design are as follows: The Buzzer is On whenever the Door is Open OR when the Key is in the ignition AND the seat belt is NOT buckled.
      Using Multisim, enter the Car Buzzer circuit shown below. Use switches for the inputs Seatbelt, Key & Door and a probe for the output Buzzer.

                pr020-1.jpg

      Toggle the input switches to complete the Actual Buzzer Output column in the truth table shown below.
     
Inputs
Buzzer Output
SeatBelt
Key
Door
Actual
Expected
0
0
0
 
0
0
0
1
 
1
0
1
0
 
1
0
1
1
 
1
1
0
0
 
0
1
0
1
 
1
1
1
0
 
0
1
1
1
 
1

If the Actual Buzzer Output column matches the Expected Output column, then your first combinational logic circuit works. Email me a pdf of your circuit and completed truth table.  If the Actual Output does not match the Expected Output, review your circuit diagram and make any necessary correction and retest. 
Next step, breadboard this circuit.
 



 
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