1. Chapter 19
Electronic Technology
Preview
CRCT Preparation

2. Chapter 19
CRCT Preparation
1. What happens to the current in the circuit if the manual switch is opened?
A Current stops in the smaller loop but continues in the larger loop.
B Current stops in the larger loop but continues in the smaller loop.
C Current stops in both loops.
D The direction of the current is reversed.

3. Chapter 19
CRCT Preparation
1. What happens to the current in the circuit if the manual switch is opened?
A Current stops in the smaller loop but continues in the larger loop.
B Current stops in the larger loop but continues in the smaller loop.
C Current stops in both loops.
D The direction of the current is reversed.

4. Chapter 19
CRCT Preparation
2. Quinyana is using the circuit diagram to design a sound amplifier. She replaced the manual switch with a microphone. What other part should she replace?
A She should replace the transistor with a speaker.
B She should replace the transistor with a volume control dial.
C She should replace the motor with a speaker.
D She should replace the motor with a volume control dial.

5. Chapter 19
CRCT Preparation
2. Quinyana is using the circuit diagram to design a sound amplifier. She replaced the manual switch with a microphone. What other part should she replace?
A She should replace the transistor with a speaker.
B She should replace the transistor with a volume control dial.
C She should replace the motor with a speaker.
D She should replace the motor with a volume control dial.

6. Chapter 19
CRCT Preparation
3. A company produces electronic components that are used in radios to convert alternating current (AC) to direct current (DC). On one assembly line, machines layer an n-type semi-conductor into a mold. What else should be added to complete the component?
A one n-type semiconductor
B one p-type semiconductor
C two p-type semiconductors
D one p-type semiconductor and one n-type semiconductor

7. Chapter 19
CRCT Preparation
3. A company produces electronic components that are used in radios to convert alternating current (AC) to direct current (DC). On one assembly line, machines layer an n-type semi-conductor into a mold. What else should be added to complete the component?
A one n-type semiconductor
B one p-type semiconductor
C two p-type semiconductors
D one p-type semiconductor and one n-type semiconductor

8. Chapter 19
CRCT Preparation
4. Which of these devices converts sound energy into electrical energy?
A telephone
B speaker
C digital alarm clock
D remote control

9. Chapter 19
CRCT Preparation
4. Which of these devices converts sound energy into electrical energy?
A telephone
B speaker
C digital alarm clock
D remote control

10. Chapter 19
CRCT Preparation
5. Laptop computers have very thin screens. How might a laptop computer screen produce images?
A Electron beams sweep the screen and cause fluorescent materials to glow.
B Laser beams shine behind the screen and create patterns of reflected light.
C Vibrations in thousands of electron tubes transfer energy to wells of colored light.
D Charged atoms of gas in wells on the screen transfer energy to fluorescent materials.

11. Chapter 19
CRCT Preparation
5. Laptop computers have very thin screens. How might a laptop computer screen produce images?
A Electron beams sweep the screen and cause fluorescent materials to glow.
B Laser beams shine behind the screen and create patterns of reflected light.
C Vibrations in thousands of electron tubes transfer energy to wells of colored light.
D Charged atoms of gas in wells on the screen transfer energy to fluorescent materials.

12. Chapter 19
CRCT Preparation
6. Cecily uses a remote control to turn on her DVD player. What kind of hardware is the remote?
A a central processing unit
B an input device
C an output device
D an interface card

13. Chapter 19
CRCT Preparation
6. Cecily uses a remote control to turn on her DVD player. What kind of hardware is the remote?
A a central processing unit
B an input device
C an output device
D an interface card

14. Chapter 19
CRCT Preparation
7. Which element in the table could be used with silicon to make a p-type semiconductor?
A boron
B germanium
C phosphorus
D selenium

15. Chapter 19
CRCT Preparation
7. Which element in the table could be used with silicon to make a p-type semiconductor?
A boron
B germanium
C phosphorus
D selenium

16. Chapter 19 8. Which of the following works in an analog way?
CRCT Preparation
8. Which of the following works in an analog way?
A a remote control for a television
B a volume control dial on a stereo
C a programmable thermostat
D a light switch

17. Chapter 19 8. Which of the following works in an analog way?
CRCT Preparation
8. Which of the following works in an analog way?
A a remote control for a television
B a volume control dial on a stereo
C a programmable thermostat
D a light switch

18. Chapter 19
CRCT Preparation
9. Why do remote-controlled toy cars contain transistors instead of vacuum tubes?
A Transistors change AC to DC, but vacuum tubes do not.
B Transistors amplify electric current, but vacuum tubes do not.
C Transistors are energy sources, but vacuum tubes are not.
D Transistors are small and light, but vacuum tubes are not.

19. Chapter 19
CRCT Preparation
9. Why do remote-controlled toy cars contain transistors instead of vacuum tubes?
A Transistors change AC to DC, but vacuum tubes do not.
B Transistors amplify electric current, but vacuum tubes do not.
C Transistors are energy sources, but vacuum tubes are not.
D Transistors are small and light, but vacuum tubes are not.

20. Chapter 19
CRCT Preparation
10. Would a diode containing only two p-type semiconductors conduct an electric current? Explain your answer.

21. Chapter 19
CRCT Preparation
10. Answer - This diode would not conduct an electric current. Full-credit answers should include the following points:
• A diode needs a p-type and an n-type semiconductor to create a current.
• When layers are joined, extra electrons from the n-type layer flow to plug holes in the p-type layer. An electric current is created when an energy source is connected such that the positive terminal is closest to the p-type semiconductor.
• If two p-type semiconductors were joined together, there would be no extra electrons to fill in the holes. Therefore, a diode with only two p-type layers would not conduct more than a very weak electric current.

22. Chapter 19
CRCT Preparation
11. Telephones and radios are similar because they both convert signals into sound waves. Describe two ways in which telephones and radios are different.

23. Chapter 19 11. Answers may include:
CRCT Preparation
11. Answers may include:
• In telephones, signals are transmitted by electric current to and from the telephone receiver. In radios, signals are transmitted by modulated radio waves from a radio station to a radio receiver.
• Telephones are also different from radios because telephones transmit and receive signals. Most commercial radios just receive signals.