COMPLETE SOLUTION MANUAL PROGRAMMABLE LOGIC
CONTROLLERS 5TH EDITION PETRUZELLA 250
QUESTIONS AND ANSWERS WITH RATIONALES CHAPTER
1 TO 15 2026 2027 COURSE PLC FUNDAMENTALS
INDUSTRIAL AUTOMATION LOGIC SEQUENCING
PROGRAMMING TROUBLESHOOTING APPLICATIONS
DETAILED EXPLANATIONS HIGH YIELD STUDY GUIDE
COMPLETE REVIEW MATERIAL GRADED A+
The central processing unit
a. looks at the inputs, makes the decisions based on the program, and sets the outputs
b. looks at the outputs, makes the decisions based on the program, and sets the inputs
c. serves only to store the program in memory
d. serves only to supply power to the backplane - CORRECT ANSWER -a
PLC proprietary architecture
a. is the opposite to open architecture
b. makes it more difficult to connect to decides made by other PLC manufacturers
c. does not allow programs to be interchanged between different PLC manufacturers
d. all of the above - CORRECT ANSWER -a
The output interface module connects to
a. sensing devices such as switches or pushbuttons
b. load devices such as lamps and solenoids
c. a programming device such as a computer
d. all of the above - CORRECT ANSWER -b
,Field or real-world devices refer to a.
input devices only
b. output devices only
c. load devices only
d. all devices that are physically wired to the PLC - CORRECT ANSWER -
d
The power required to operate the logic circuits of the processor unit is typically a. low-
voltage AC
b. high-voltage AC
c. low-voltage DC
d. high-voltage DC - CORRECT ANSWER -c
The control plan stored in the PLC is called a. a
program
b. a Boolean ladder
c. FORTRAN
d. a microprocessor - CORRECT ANSWER -a
The programming device
a. is used to enter the program into the memory of the processor
b. is commonly a personal computer
c. can be a handheld device
d. all of the above - CORRECT ANSWER -d
The programming device must be connected to the controller a. at all
times
,b. when entering a program
c. when monitoring a program
d. both b and c - CORRECT ANSWER -d
At the start of the PLC scan the a.
status of all inputs is read
b. status of all outputs is updated
c. program is executed
d. diagnostics and communications tasks are executed - CORRECT
ANSWER -a
The scan time is the time required
a. to record the status of all input devices
b. to record the status of all output devices
c. to execute one cycle of the total program
d. for the information to pass from input to output - CORRECT ANSWER c
Unlike personal computers, PLCs are
a. equipped with input and output modules
b. equipped with a control programming language
c. designed for the industrial environment
d. all of the above - CORRECT ANSWER -d
A human machine interface (HMI)
a. allows the user to monitor a process
b. allows the user to control a process
c. can provide a graphical representation of a process
, d. all of the above - CORRECT ANSWER -d
Programmable logic controllers are categorized according to the a.
number of I/O points
b. current rating of I/O modules
c. power rating of I/O modules
d. cost of I/O modules - CORRECT ANSWER -a
The PLC power supply module normally is rated to provide the power for a. all field
devices
b. input field devices only
c. output field devices only
d. PLC backplane and I/O modules - CORRECT ANSWER -d
Which module of the PLC is responsible for performing logical operations? a.
Processor
b. Input
c. Output
d. Power Supply - CORRECT ANSWER -a
Which module of the PLC connects directly to field devices such as pilot lights, motor
starters, and solenoids? a. Input
b. Output
c. Power Supply
d. Memory - CORRECT ANSWER -b
CONTROLLERS 5TH EDITION PETRUZELLA 250
QUESTIONS AND ANSWERS WITH RATIONALES CHAPTER
1 TO 15 2026 2027 COURSE PLC FUNDAMENTALS
INDUSTRIAL AUTOMATION LOGIC SEQUENCING
PROGRAMMING TROUBLESHOOTING APPLICATIONS
DETAILED EXPLANATIONS HIGH YIELD STUDY GUIDE
COMPLETE REVIEW MATERIAL GRADED A+
The central processing unit
a. looks at the inputs, makes the decisions based on the program, and sets the outputs
b. looks at the outputs, makes the decisions based on the program, and sets the inputs
c. serves only to store the program in memory
d. serves only to supply power to the backplane - CORRECT ANSWER -a
PLC proprietary architecture
a. is the opposite to open architecture
b. makes it more difficult to connect to decides made by other PLC manufacturers
c. does not allow programs to be interchanged between different PLC manufacturers
d. all of the above - CORRECT ANSWER -a
The output interface module connects to
a. sensing devices such as switches or pushbuttons
b. load devices such as lamps and solenoids
c. a programming device such as a computer
d. all of the above - CORRECT ANSWER -b
,Field or real-world devices refer to a.
input devices only
b. output devices only
c. load devices only
d. all devices that are physically wired to the PLC - CORRECT ANSWER -
d
The power required to operate the logic circuits of the processor unit is typically a. low-
voltage AC
b. high-voltage AC
c. low-voltage DC
d. high-voltage DC - CORRECT ANSWER -c
The control plan stored in the PLC is called a. a
program
b. a Boolean ladder
c. FORTRAN
d. a microprocessor - CORRECT ANSWER -a
The programming device
a. is used to enter the program into the memory of the processor
b. is commonly a personal computer
c. can be a handheld device
d. all of the above - CORRECT ANSWER -d
The programming device must be connected to the controller a. at all
times
,b. when entering a program
c. when monitoring a program
d. both b and c - CORRECT ANSWER -d
At the start of the PLC scan the a.
status of all inputs is read
b. status of all outputs is updated
c. program is executed
d. diagnostics and communications tasks are executed - CORRECT
ANSWER -a
The scan time is the time required
a. to record the status of all input devices
b. to record the status of all output devices
c. to execute one cycle of the total program
d. for the information to pass from input to output - CORRECT ANSWER c
Unlike personal computers, PLCs are
a. equipped with input and output modules
b. equipped with a control programming language
c. designed for the industrial environment
d. all of the above - CORRECT ANSWER -d
A human machine interface (HMI)
a. allows the user to monitor a process
b. allows the user to control a process
c. can provide a graphical representation of a process
, d. all of the above - CORRECT ANSWER -d
Programmable logic controllers are categorized according to the a.
number of I/O points
b. current rating of I/O modules
c. power rating of I/O modules
d. cost of I/O modules - CORRECT ANSWER -a
The PLC power supply module normally is rated to provide the power for a. all field
devices
b. input field devices only
c. output field devices only
d. PLC backplane and I/O modules - CORRECT ANSWER -d
Which module of the PLC is responsible for performing logical operations? a.
Processor
b. Input
c. Output
d. Power Supply - CORRECT ANSWER -a
Which module of the PLC connects directly to field devices such as pilot lights, motor
starters, and solenoids? a. Input
b. Output
c. Power Supply
d. Memory - CORRECT ANSWER -b
