Electronic Technology

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