Question 1

Figure 20-12 
-What does the accompanying figure show?

Accepted Answer

The figure shows a photodetector used to detect the presence of an object on the conveyor line. When the object passes between the transmitter and receiver units, the light beam is broken and the detector activates.

Question 2

Figure 20-09 
-In the circuit shown in the accompanying figure, although the circuit will work if the cad cell is large enough to handle the current, there are still two problems. What are they?

Accepted Answer

The two problems are:
1) There...

Question 3

Regardless of the type of photoemissive device used, or the type circuit it is used in, the greatest advantage of the photoemissive device is ____________________.

Accepted Answer

The answer of Regardless of the type of photoemissive device...

Question 4

Figure 20-01 
-The accompanying figure shows the schematic symbol for a photovoltaic cell. What do the battery and arrow symbols mean?

Accepted Answer

The battery symbol means the d...

Question 5

The most common photoconductive device is the ____________________.

Accepted Answer

cadmium sulfide cell
cad cell

Question 6

Photoconductive devices exhibit a change of resistance due to the presence or absence of light.

Accepted Answer

A) True 
 B)False

Question 7

A(n) ____________________ steals the base current away from some other transistor to keep it turned off.

Accepted Answer

The answer of A(n) ____________________ steals the base current away...

Question 8

The amount of voltage produced by a cell is determined by the material of which it is made.

Accepted Answer

A) True 
 B)False

Question 9

Photodetectors have to make physical contact with the object they are sensing.

Accepted Answer

A) True 
 B)False

Question 10

Photovoltaic devices are more often called ____________________.

Accepted Answer

solar cells

Question 11

Photo-operated devices fall into one of three categories. What are the categories?

Accepted Answer

Photo-operated devices fall in...

Question 12

Figure 20-04 
-The circuit in the accompanying figure shows a phototransistor used to turn on a relay coil. What is the difference when the phototransistor is in the presence of darkness versus light?

Accepted Answer

When the phototransistor is in darkness,...

Question 13

Photodetectors that have both the transmitter and the receiver units mounted in the same housing depend on a reflector for operation.

Accepted Answer

A) True 
 B)False

Question 14

Photovoltaic cells cannot operate electrical equipment without external power.

Accepted Answer

A) True 
 B)False

Question 15

____________________ emit electrons when in the presence of light.

Accepted Answer

Photoemiss...

Exam 20: Photodetectors

Figure 20-12 -What does the accompanying figure show?

Correct Answer
verified
The figure shows a photodetector used to detect the presence of an object on the conveyor line. When the object passes between the transmitter and receiver units, the light beam is broken and the detector activates.

Figure 20-09 -In the circuit shown in the accompanying figure, although the circuit will work if the cad cell is large enough to handle the current, there are still two problems. What are they?

Correct Answer
verified
The two problems are:
1) There...
View Answer

Regardless of the type of photoemissive device used, or the type circuit it is used in, the greatest advantage of the photoemissive device is ____________________.

Correct Answer
verified

Figure 20-01 -The accompanying figure shows the schematic symbol for a photovoltaic cell. What do the battery and arrow symbols mean?

Correct Answer
verified
The battery symbol means the d...
View Answer

The most common photoconductive device is the ____________________.

Correct Answer
verified
cadmium sulfide cell cad cell

Photoconductive devices exhibit a change of resistance due to the presence or absence of light.

Correct Answer
verified

A(n) ____________________ steals the base current away from some other transistor to keep it turned off.

Correct Answer
verified

The amount of voltage produced by a cell is determined by the material of which it is made.

Correct Answer
verified

Photodetectors have to make physical contact with the object they are sensing.

Correct Answer
verified

Photovoltaic devices are more often called ____________________.

Correct Answer
verified
solar cells

Photo-operated devices fall into one of three categories. What are the categories?

Correct Answer
verified
Photo-operated devices fall in...
View Answer

Figure 20-04 -The circuit in the accompanying figure shows a phototransistor used to turn on a relay coil. What is the difference when the phototransistor is in the presence of darkness versus light?

Correct Answer
verified
When the phototransistor is in darkness,...
View Answer

Photodetectors that have both the transmitter and the receiver units mounted in the same housing depend on a reflector for operation.

Correct Answer
verified

Photovoltaic cells cannot operate electrical equipment without external power.

Correct Answer
verified

____________________ emit electrons when in the presence of light.

Correct Answer
verified
Photoemiss...
View Answer

Exam 20: Photodetectors

Figure 20-12 -What does the accompanying figure show?

Correct AnswerverifiedThe figure shows a photodetector used to detect the presence of an object on the conveyor line. When the object passes between the transmitter and receiver units, the light beam is broken and the detector activates.

Figure 20-09 -In the circuit shown in the accompanying figure, although the circuit will work if the cad cell is large enough to handle the current, there are still two problems. What are they?

Correct AnswerverifiedThe two problems are:1) There...View AnswerShow Answer

Regardless of the type of photoemissive device used, or the type circuit it is used in, the greatest advantage of the photoemissive device is ____________________.

Correct AnswerverifiedShow Answer

Figure 20-01 -The accompanying figure shows the schematic symbol for a photovoltaic cell. What do the battery and arrow symbols mean?

Correct AnswerverifiedThe battery symbol means the d...View AnswerShow Answer

The most common photoconductive device is the ____________________.

Correct Answerverifiedcadmium sulfide cell cad cell

Photoconductive devices exhibit a change of resistance due to the presence or absence of light.

Correct AnswerverifiedShow Answer

A(n) ____________________ steals the base current away from some other transistor to keep it turned off.

Correct AnswerverifiedShow Answer

The amount of voltage produced by a cell is determined by the material of which it is made.

Correct AnswerverifiedShow Answer

Photodetectors have to make physical contact with the object they are sensing.

Correct AnswerverifiedShow Answer

Photovoltaic devices are more often called ____________________.

Correct Answerverifiedsolar cells

Photo-operated devices fall into one of three categories. What are the categories?

Correct AnswerverifiedPhoto-operated devices fall in...View AnswerShow Answer

Figure 20-04 -The circuit in the accompanying figure shows a phototransistor used to turn on a relay coil. What is the difference when the phototransistor is in the presence of darkness versus light?

Correct AnswerverifiedWhen the phototransistor is in darkness,...View AnswerShow Answer

Photodetectors that have both the transmitter and the receiver units mounted in the same housing depend on a reflector for operation.

Correct AnswerverifiedShow Answer

Photovoltaic cells cannot operate electrical equipment without external power.

Correct AnswerverifiedShow Answer

____________________ emit electrons when in the presence of light.

Correct AnswerverifiedPhotoemiss...View AnswerShow Answer

Correct Answer
verified
The figure shows a photodetector used to detect the presence of an object on the conveyor line. When the object passes between the transmitter and receiver units, the light beam is broken and the detector activates.

Correct Answer
verified
The two problems are:
1) There...
View Answer

Correct Answer
verified

Correct Answer
verified
The battery symbol means the d...
View Answer

Correct Answer
verified
cadmium sulfide cell cad cell

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
solar cells

Correct Answer
verified
Photo-operated devices fall in...
View Answer

Correct Answer
verified
When the phototransistor is in darkness,...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
Photoemiss...
View Answer