MC II: Lesson 3 - Solid State Motor Control Pilot Devices

Question 1

The output signal of a discrete sensor can only be on or off.

True or False

Answer 1

True

Question 2

Discrete mechanical sensors have contacts that open and close. Since discrete electronic sensors often do not have mechanical contacts, the output condition is described as activated or de-activated.

True or False

Answer 2

True

Question 3

Capacitive, inductive and ultrasonic are three types of ______ sensors that are based on the sensor’s operating principles.

a. analog
b. contact
c. photoelectric
d. proximity

Answer 3

d. proximity

Question 4

Since solid-state sensors use semiconductor circuits instead of contacts to switch the attached load, the load must match the voltage and current specifications for the sensor.

True or False

Answer 4

True

Question 5

Sensors that use an NPN transistor to switch DC loads are current-______ devices.

a. sinking
b. sourcing

Answer 5

a. sinking

Question 6

Current-sinking outputs use the ______ side of the DC output circuit as the switch leg to the load device.

a. negative
b. positive

Answer 6

a. negative

Question 7

Sensors that use a PNP transistor to switch DC loads are current- ______ devices.

a. sinking
b. sourcing

Answer 7

b. sourcing

Question 8

Current-sourcing outputs use the ______ side of the DC output circuit as the switch leg to the load device.

a. negative
b. positive

Answer 8

b. positive

Question 9

Identify the NEMA symbol with the correct 3-wire sensor.

Answer 9

Question 10

______ devices are non-contact solid-state devices that use light to detect the presence of objects.

a. Hall effect
b. Photoelectric
c. Triac
d. SCR

Answer 10

b. Photoelectric

Question 11

Electronic sensors with a(n) ______ output interface can switch AC or DC without the specific polarity requirements for DC circuits.

a. BJT
b. FET
c. Relay
d. SCR

Answer 11

c. Relay

Question 12

A photocell is a photoelectric device that only reacts to ______ light.

a. ambient
b. laser
c. LED
d. sun

Answer 12

a. ambient

Question 13

The component present in a photoelectric device that provides a light source is a ______.

a. receiver
b. transmitter

Answer 13

b. transmitter

Question 14

The component present in a photoelectric device that detects the presence of the light source is a ______.

a. receiver
b. transmitter

Answer 14

a. receiver

Question 15

Response time, sensitivity, operation margin, and light/dark operation are four parameters that are commonly used to describe the operation of ______ devices.

a. contact
b. Hall effect
c. photoelectric
d. proximity

Answer 15

c. photoelectric

Question 16

______ is measured by the number of light pulses per second that a photoelectric device transmits.

a. Light/dark operation
b. Operating margin
c. Response time
d. Sensitivity

Answer 16

c. Response time

Question 17

______ is the threshold value for received light to trigger a change in the output status of a photoelectric device.

a. Light/dark operation
b. Operating margin
c. Response time
d. Sensitivity

Answer 17

d. Sensitivity

Question 18

The ratio of the available level of light at a photoelectric sensor’s receiver to the minimum level of light required to trigger the sensor is the ______.

a. light/dark operation
b. operating margin
c. response time
d. sensitivity

Answer 18

b. operating margin

Question 19

A ______ operating margin indicates that a sensor will be reliable when ambient light conditions are variable.

a. higher
b. lower

Answer 19

a. higher

Question 20

The ______ modes enable a photoelectric sensor to detect whether a target is present or absent.

a. light/dark operation
b. operating margin
c. response time
d. sensitivity

Answer 20

a. light/dark operation

Question 21

What is the photoelectric scanning method in which the transmitter and receiver are placed opposite each other?

a. Diffuse
b. Direct
c. Polarized
d. Retroreflective

Answer 21

b. Direct

Question 22

What is the photoelectric scanning method in which the transmitter and receiver are housed in the same enclosure and the transmitted beam is reflected back to the receiver from a reflector?

a. Diffuse
b. Direct
c. Polarized
d. Retroreflective

Answer 22

d. Retroreflective

Question 23

What is the photoelectric scanning method in which the receiver responds only to the depolarized reflected light from a special reflector or polarized sensitive reflective tape?

a. Diffuse
b. Direct
c. Polarized
d. Retroreflective

Answer 23

c. Polarized

Question 24

What is the photoelectric scanning method in which the transmitter and receiver are housed in the same enclosure and in which a specialized scanning technique is used not only to determine when an object is moved into position but also to identify the specific location of the object?

a. Diffuse
b. Direct
c. Polarized
d. Retroreflective

Answer 24

a. Diffuse

Question 25

Proximity sensors that detect objects using an electrostatic field are known as _____ devices. a. capacitive b. inductive

Answer 25

a. capacitive

Question 26

Proximity sensors that detect objects using an electromagnetic field are known as ______ devices. a. capacitive b. inductive

Answer 26

b. inductive

Question 27

______ proximity sensors can only detect metals that conduct current. a. Capacitive b. Hall effect c. Inductive d. Ultrasonic

Answer 27

c. Inductive

Question 28

The size of the object and the type of metal (ferrous or nonferrous) are two factors that determine the effective sensing range of a(n) _____ proximity sensor. a. capacitive b. inductive c. ultrasonic

Answer 28

b. inductive

Question 29

A(n) ______ proximity sensor can detect a wide range of materials, including metals (ferrous and nonferrous), glass, plastics, and liquids. a. capacitive b. inductive c. ultrasonic

Answer 29

a. capacitive

Question 30

The size and dielectric properties of the object are the two factors that determine the effective sensing range of a ______ proximity sensor. a. capacitive b. inductive c. ultrasonic

Question 31

What type of proximity sensor emits a high frequency sound signal and detects the reflected sound from the object? a. Capacitive b. Inductive c. Ultrasonic

Answer 31

c. Ultrasonic

Question 32

______ devices are solid-state sensors that detect the presence of a magnetic field. a. Capacitive b. Hall effect c. Inductive d. Ultrasonic

Answer 32

b. Hall effect

Question 33

A primary step in troubleshooting any of the sensors covered is to determine if the sensor has the correct operating input voltage. True or False

Answer 33

True

Question 34

The sensor in an IEC Standard NPN device must be connected to provide a ______ connection to the load. a. sinking b. sourcing

Answer 34

a. sinking

Question 35

The IEC Standard PNP device must be connected to provide a ______ connection to the load. a. sinking b. sourcing

Answer 35

b. sourcing