Input and Output Devices

Question 1

The drum switch is a ___-position switch that can be used manually to change the direction of rotation of a 3-phase motor.

A) two
B) three
C) four
D) none of the listed answers

Answer 1

B) three

Question 2

Limit switches must be selected appropriately and mounted correctly. Which statements are correct installation guidelines to follow for limit switch installations?

I. Mount limit switches rigidly and in easily accessible locations.
II. Mount where heat exceeds specified limits.
III. Mount where over-travel from the machine operator is possible.
IV. Provide adequate clearance for easy service and replacement.

A) I. and II.
B) I., II., III., and IV.
C) I. and IV.
D) II., III., and IV.

Answer 2

C) I. and IV.

Question 3

A sub class of limit switches, ___ switches have similar physical and electrical characteristics.

A) end
B) macro
C) micro
D) pressure

Answer 3

C) micro

Question 4

When installing pushbutton or selector switches, ___ type operators are generally installed in 30.5 millimeter openings, while ___ type operators are generally installed in 16 millimeter or 22.5 millimeter openings.

A) IEC / NEMA
B) NEMA / IEC

Answer 4

B) NEMA / IEC

Question 5

___ is the visual signaling color for an emergency or dangerous situations.

A) Blue
B) Clear
C) Green
D) Red

Answer 5

D) Red

Question 6

Boilers, cooling lines, air compressors, and fluid pumps are examples of where a ___ switch might be used.

A) flow
B) level
C) pressure
D) temperature

Answer 6

A) flow

Question 7

Match the pressure ranges with the three most common pressure sensing devices.

I. Low pressure measurements up to 300 psi; depending on the membrane
II. Medium pressure applications up to 2,000 psi
III. High pressure applications up to 15,000 psi

A) Bellows
B) Piston
C) Diaphragm

Answer 7

I. - C
II. - A
III. - B

Question 8

Bimetallic strip, capillary tube, and direct immersion probes are three frequently used mechanical ___ sensing devices.

A) flow
B) level
C) pressure
D) temperature

Answer 8

D) temperature

Question 9

The ___ is a temperature sensing device that bends when the temperature changes. It is made up of two dissimilar metals that have different expansion and contraction rates when heated and cooled.

A) bimetallic strip
B) capillary tube
C) direct immersion probe

Answer 9

A) bimetallic strip

Question 10

To move a crane using a joystick switch, it would only require only four contacts if the crane required the following operations: UP, DOWN, LEFT, and RIGHT.

A) True
B) False

Answer 10

A) True

Question 11

___ switches are often used in equipment enclosures to detect open panel doors and missing equipment guards.

A) Flow
B) Level
C) Miniature
D) Pressure

Answer 11

C) Miniature

Question 11

The force applied to the actuator required to operate the switch contacts is called ___.

A) operating force (OF)
B) releasing force (RF)
C) switching force (SF)
D) total force (TF)

Answer 11

A) operating force (OF)

Question 11

The two parts of a pushbutton switch are the operator and the ___ block.

A) contact
B) drum
C) operator
D) relay

Answer 11

A) contact

Question 12

___ switches fuction when gas or liquid is removed from a system.

A) Differential pressure
B) Positive pressure
C) Vacuum (negative pressure)

Answer 12

C) Vacuum (negative pressure)

Question 13

Which two types of visual indicators are normally associated with a hazard problem or a proceed-with-caution indication?

I. Flood beacon
II. Flashing beacon
III. Rotating beacon
IV. Spot beacon

A) I. and II.
B) I. and III.
C) II. and III.
D) III. and IV.

Answer 13

C) II. and III.