Chapters 5 & 6 Review Questions

Question 1

Scan time varies with program content and length.

Answer 1

True

Question 2

When the XIO instruction is associated with a physical input, the instruction will be set to 1 when there is no input voltage applied to the terminal.

Answer 2

True

Question 3

The status of the OTE instruction is set to 1 to energize the output and to de-energize the output.

Answer 3

True

Question 4

Each individual contact instruction can be used only once through the program.

Answer 4

False

Question 5

Series logic could also be called OR logic

Answer 5

False

Question 6

Ladder logic is a symbolic language.

Answer 6

True

Question 7

A programmed XIO instruction:
A. with a bit status of 1 will not have logic continuity.
B. is examined for an OFF condition.
C. is examined for an ON condition.
D. both a and b.

Answer 7

D

Question 8

When using an XIC instruction, the reference address could be:
A. a bit from an input device.
B. a bit from an output device.
C. a bit from an internal relay.
D. any of these

Answer 8

D

Question 9

A normally open limit switch is wired to an input module, and programmed using XIO instruction. The instruction will be true when:
A. the power is applied and the PLC is in the run mode.
B. the limit switch is closed.
C. the limit switch is open.
D. never

Answer 9

C

Question 10

An electromechanical relay uses electromagnetism to operate contacts.

Answer 10

True

Question 11

In general, PLC output modules are designed to switch high current loads directly.

Answer 11

False

Question 12

A selector switch is rotated to open and close contacts.

Answer 12

True

Question 13

A small current flows through a solid-state proximity sensor even when the output is turned OFF.

Answer 13

True

Question 14

Fiber optic sensor systems are completely immune to all forms of electrical interference.

Answer 14

True

Question 15

The programmed latching relay instruction is retentive; that is, if the relay is latched it will unlatch if power is lost and then restored.

Answer 15

False

Question 16

A proximity switch can be actuated:
A. without any physical contact.
B. by a change in light intensity.
C. by a change in capacitance.
D. by all of these

Answer 16

D

Question 17

Fiber optic sensors:
A. are not affected by electrical interference.
B. carry light signal signals.
C. use a flexible cable containing tiny fibers.
D. All the above

Answer 17

D

Question 18

Bar code scanners are used primarily for:
A. data collection
B. temperature measurement
C. pressure measurement
D. flow measurement

Answer 18

A

Question 19

An actuator is a device that:
A. changes AC to DC.
B. changes DC to AC.
C. converts an electrical signal into mechanical movement.
D. converts mechanical movement into an electrical signal.

Answer 19

C