1Which component is commonly used to limit the flow of electric current?
Familiarization of electronic components
Easy
A.Transistor
B.Diode
C.Capacitor
D.Resistor
Correct Answer: Resistor
Explanation:
A resistor opposes and limits the flow of electric current in a circuit.
Incorrect! Try again.
2Which component stores electrical energy in an electric field?
Familiarization of electronic components
Easy
A.Diode
B.Capacitor
C.Fuse
D.Resistor
Correct Answer: Capacitor
Explanation:
A capacitor stores electrical energy in the electric field between its plates.
Incorrect! Try again.
3What is the main function of a diode in a simple circuit?
Familiarization of electronic components
Easy
A.To store current in two directions
B.To allow current in one direction
C.To increase resistance in all directions
D.To produce sound from light
Correct Answer: To allow current in one direction
Explanation:
A diode conducts current mainly in one direction and blocks it in the opposite direction.
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4What does LED stand for?
Familiarization of electronic components
Easy
A.Light Emitting Diode
B.Low Energy Device
C.Linear Electrical Display
D.Light Energy Detector
Correct Answer: Light Emitting Diode
Explanation:
LED stands for Light Emitting Diode. It emits light when current flows through it in the forward direction.
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5Which component is commonly used as an electronic switch or amplifier?
Familiarization of electronic components
Easy
A.Inductor
B.Capacitor
C.Resistor
D.Transistor
Correct Answer: Transistor
Explanation:
A transistor can operate as an electronic switch or as an amplifier.
Incorrect! Try again.
6What is the purpose of a fuse in an electronic circuit?
Familiarization of electronic components
Easy
A.To store electrical charge
B.To protect against excessive current
C.To increase the supply voltage
D.To display a binary number
Correct Answer: To protect against excessive current
Explanation:
A fuse melts and opens the circuit when the current becomes dangerously high.
Incorrect! Try again.
7Which component is designed to store energy in a magnetic field?
Familiarization of electronic components
Easy
A.Resistor
B.Inductor
C.LED
D.Diode
Correct Answer: Inductor
Explanation:
An inductor stores energy in the magnetic field produced by current through its coil.
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8What is an integrated circuit, commonly called an IC?
Familiarization of electronic components
Easy
A.A single wire with insulation
B.A device used only for measuring voltage
C.A group of circuits on one chip
D.A mechanical switch with many contacts
Correct Answer: A group of circuits on one chip
Explanation:
An IC contains many electronic components and circuits fabricated on a single semiconductor chip.
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9What is the main purpose of a digital trainer module?
Familiarization of the digital trainer module
Easy
A.To charge batteries automatically
B.To measure room temperature only
C.To convert mechanical motion into sound
D.To test and build digital circuits
Correct Answer: To test and build digital circuits
Explanation:
A digital trainer module provides facilities for connecting, testing, and observing digital circuits.
Incorrect! Try again.
10Which source on a digital trainer is commonly used to provide logic 0 or logic 1 inputs?
Familiarization of the digital trainer module
Easy
A.Heat sink
B.Logic switch
C.Speaker
D.Transformer core
Correct Answer: Logic switch
Explanation:
A logic switch allows the user to select a digital input such as logic 0 or logic 1.
Incorrect! Try again.
11Which indicator on a digital trainer commonly shows the state of a logic signal?
Familiarization of the digital trainer module
Easy
A.Variable resistor
B.LED indicator
C.Power transformer
D.Fuse holder
Correct Answer: LED indicator
Explanation:
An LED indicator can glow or remain off to show the state of a digital signal.
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12What is the function of a regulated power supply in a digital trainer?
Familiarization of the digital trainer module
Easy
A.To measure resistance directly
B.To store programs permanently
C.To provide a stable DC voltage
D.To produce mechanical rotation
Correct Answer: To provide a stable DC voltage
Explanation:
A regulated power supply provides a steady DC voltage required by electronic circuits.
Incorrect! Try again.
13Which device on a digital trainer can provide regularly repeating digital pulses?
Familiarization of the digital trainer module
Easy
A.Clock generator
B.Fuse
C.Potentiometer
D.Loudspeaker
Correct Answer: Clock generator
Explanation:
A clock generator produces regularly repeating pulses used to operate timing and sequential circuits.
Incorrect! Try again.
14What does a common seven-segment display show?
Familiarization of the digital trainer module
Easy
A.Magnetic field lines
B.Decimal digits
C.Only resistance values
D.Only analog waveforms
Correct Answer: Decimal digits
Explanation:
A seven-segment display uses seven segments to represent decimal digits and some letters.
Incorrect! Try again.
15Which instrument can generate a sine wave for testing an electronic circuit?
Familiarization of input sources and display devices related to electronic circuits
Easy
A.Seven-segment display
B.Function generator
C.Digital multimeter
D.Loudspeaker
Correct Answer: Function generator
Explanation:
A function generator produces test signals such as sine, square, and triangular waves.
Incorrect! Try again.
16Which source provides a constant electrical voltage for a circuit?
Familiarization of input sources and display devices related to electronic circuits
Easy
A.Microphone
B.DC power supply
C.LED display
D.Oscilloscope
Correct Answer: DC power supply
Explanation:
A DC power supply provides a steady direct voltage to operate an electronic circuit.
Incorrect! Try again.
17Which device converts sound waves into an electrical signal?
Familiarization of input sources and display devices related to electronic circuits
Easy
A.Microphone
B.Relay
C.Lamp
D.Speaker
Correct Answer: Microphone
Explanation:
A microphone senses sound waves and converts them into an electrical signal.
Incorrect! Try again.
18Which device converts an electrical signal into sound?
Familiarization of input sources and display devices related to electronic circuits
Easy
A.Resistor
B.Speaker
C.Photodiode
D.Microphone
Correct Answer: Speaker
Explanation:
A speaker converts electrical signals into sound waves.
Incorrect! Try again.
19Which instrument is used to observe the waveform of an electrical signal?
Familiarization of input sources and display devices related to electronic circuits
Easy
A.Function switch
B.Soldering iron
C.Oscilloscope
D.Battery holder
Correct Answer: Oscilloscope
Explanation:
An oscilloscope displays the variation of voltage with time as a waveform.
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20Which display device uses liquid crystals to show information?
Familiarization of input sources and display devices related to electronic circuits
Easy
A.LCD
B.Diode
C.Transformer
D.LED
Correct Answer: LCD
Explanation:
LCD stands for Liquid Crystal Display and uses liquid crystals to display numbers, symbols, or images.
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21A resistor with color bands brown, black, and red has an approximate resistance of:
Familiarization of electronic components
Medium
A.
B.
C.
D.
Correct Answer:
Explanation:
The first two bands give 10, and the red multiplier adds two zeros, giving .
Incorrect! Try again.
22A circuit requires a supply and a component must be limited to . What resistor value is closest for a simple series connection when the component drop is negligible?
Familiarization of electronic components
Medium
A.
B.
C.
D.
Correct Answer:
Explanation:
Using Ohm's law, .
Incorrect! Try again.
23Which component is most suitable for allowing current in one direction while blocking it in the opposite direction?
Familiarization of electronic components
Medium
A.Transformer
B.Diode
C.Resistor
D.Capacitor
Correct Answer: Diode
Explanation:
A diode conducts primarily in its forward-bias direction and blocks current when reverse biased, within its ratings.
Incorrect! Try again.
24An electrolytic capacitor is connected directly across a DC supply. Which practice is essential?
Familiarization of electronic components
Medium
A.Connect it without polarity
B.Short its terminals initially
C.Match its polarity correctly
D.Reverse its marked terminals
Correct Answer: Match its polarity correctly
Explanation:
Electrolytic capacitors are polarized. Incorrect polarity can cause leakage, heating, or failure.
Incorrect! Try again.
25In a transistor used as an electronic switch, the transistor is intended to operate mainly in which two regions?
Familiarization of electronic components
Medium
A.Cutoff and saturation
B.Active and breakdown
C.Leakage and thermal
D.Reverse and avalanche
Correct Answer: Cutoff and saturation
Explanation:
Cutoff represents the OFF state, while saturation represents the ON state in a transistor switching circuit.
Incorrect! Try again.
26A fuse is placed in series with the supply of an electronic circuit primarily to:
Familiarization of electronic components
Medium
A.Protect against excessive current
B.Increase the circuit voltage
C.Limit normal signal frequency
D.Improve the circuit power factor
Correct Answer: Protect against excessive current
Explanation:
A fuse melts when current exceeds its rated value, opening the circuit and protecting wiring and components.
Incorrect! Try again.
27Which component is commonly used to vary resistance manually in order to adjust voltage or signal level?
Familiarization of electronic components
Medium
A.Crystal oscillator
B.Potentiometer
C.Rectifier diode
D.Photodiode
Correct Answer: Potentiometer
Explanation:
A potentiometer provides an adjustable resistance or voltage-divider output using a movable wiper.
Incorrect! Try again.
28Before connecting an IC on a digital trainer module, the safest first action is to:
Familiarization of the digital trainer module
Medium
A.Apply the maximum supply voltage
B.Short the output terminals
C.Connect every input to ground
D.Switch off the module supply
Correct Answer: Switch off the module supply
Explanation:
Powering down before inserting or removing an IC reduces the risk of accidental shorts and component damage.
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29A digital trainer's logic switch is connected to an IC input. What is its main purpose?
Familiarization of the digital trainer module
Medium
A.To measure analog resistance
B.To display the circuit waveform
C.To provide selectable logic levels
D.To amplify output current continuously
Correct Answer: To provide selectable logic levels
Explanation:
Logic switches allow the user to apply defined digital states, commonly logic 0 and logic 1, to circuit inputs.
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30If a trainer module's logic probe indicates a high state at an output, the output voltage is generally:
Familiarization of the digital trainer module
Medium
A.Always equal to the input voltage
B.Near the circuit ground level
C.Always equal to zero volts
D.Near the designated logic supply level
Correct Answer: Near the designated logic supply level
Explanation:
A logic-high output is normally close to the positive supply voltage, although its exact value depends on the logic family and load.
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31A seven-segment display on a trainer module shows an incorrect digit even though the logic inputs appear correct. Which check is most relevant first?
Familiarization of the digital trainer module
Medium
A.Increase the supply without measuring
B.Replace the display with a resistor
C.Disconnect the ground connection
D.Check the segment wiring and common terminal
Correct Answer: Check the segment wiring and common terminal
Explanation:
Incorrect segment connections or an unmatched common-anode/common-cathode configuration can produce an incorrect displayed digit.
Incorrect! Try again.
32What is the main function of a clock generator on a digital trainer module?
Familiarization of the digital trainer module
Medium
A.Convert DC directly into sound
B.Provide periodic digital pulses
C.Measure the resistance of an IC
D.Regulate the brightness of all LEDs
Correct Answer: Provide periodic digital pulses
Explanation:
A clock generator supplies repeated timing pulses used to operate counters, registers, and other sequential digital circuits.
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33A digital IC input is left unconnected on a trainer module. Why can this cause unreliable operation?
Familiarization of the digital trainer module
Medium
A.The input always produces a precise logic zero
B.The input permanently disables the power supply
C.The input automatically becomes a regulated output
D.The input may assume an undefined logic state
Correct Answer: The input may assume an undefined logic state
Explanation:
A floating input can pick up noise and may be interpreted unpredictably. It should be connected to a defined logic level when required.
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34When testing a logic circuit on a trainer, why should the circuit ground and instrument ground be connected properly?
Familiarization of the digital trainer module
Medium
A.To convert binary signals into analog signals
B.To establish a common voltage reference
C.To prevent all output transitions
D.To increase the logic supply frequency
Correct Answer: To establish a common voltage reference
Explanation:
A common ground reference ensures that measured and applied logic voltages are interpreted consistently by the circuit and instruments.
Incorrect! Try again.
35A function generator is connected to an amplifier input. Which setting determines how large the applied signal is?
Familiarization of input sources and display devices related to electronic circuits
Medium
A.Frequency
B.Duty-cycle label
C.Time-base scale
D.Amplitude
Correct Answer: Amplitude
Explanation:
Amplitude controls the voltage magnitude of the generated waveform, while frequency controls how rapidly it repeats.
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36A sine wave displayed on an oscilloscope occupies four vertical divisions. If the vertical scale is , what is the peak-to-peak voltage?
Familiarization of input sources and display devices related to electronic circuits
Medium
A.
B.
C.
D.
Correct Answer:
Explanation:
The peak-to-peak voltage is divisions multiplied by volts per division: .
Incorrect! Try again.
37An oscilloscope shows five complete cycles across ten horizontal divisions. If the time scale is , what is the approximate frequency?
Familiarization of input sources and display devices related to electronic circuits
Medium
A.
B.
C.
D.
Correct Answer:
Explanation:
The total time is . Five cycles give a period of , so .
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38Which input device changes its resistance significantly in response to incident light and can be used in a light-sensing circuit?
Familiarization of input sources and display devices related to electronic circuits
Medium
A.Piezoelectric buzzer
B.Thermistor
C.Relay coil
D.LDR
Correct Answer: LDR
Explanation:
An LDR, or light-dependent resistor, changes resistance according to the intensity of incident light.
Incorrect! Try again.
39A microphone is connected to an electronic circuit as an input source. It primarily converts:
Familiarization of input sources and display devices related to electronic circuits
Medium
A.DC voltage into magnetic flux
B.Digital data into heat
C.Sound into an electrical signal
D.Light into resistance
Correct Answer: Sound into an electrical signal
Explanation:
A microphone converts variations in sound pressure into a corresponding electrical signal.
Incorrect! Try again.
40Which display device is most appropriate when a circuit must indicate the ON or OFF state of a digital output immediately?
Familiarization of input sources and display devices related to electronic circuits
Medium
A.LED
B.Variable capacitor
C.Transformer
D.Thermistor
Correct Answer: LED
Explanation:
An LED provides a clear visual indication of a digital state and responds rapidly to changes in the output.
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41A resistor has the color bands brown, black, orange, and gold. During measurement with a multimeter, the value appears close to . Which conclusion is most appropriate?
Familiarization of electronic components
Hard
A.The resistor is within its stated tolerance
B.The resistor must be connected with reverse polarity
C.The gold band represents a temperature coefficient
D.The resistor should measure near
Correct Answer: The resistor is within its stated tolerance
Explanation:
Brown-black-orange gives , and gold indicates . The acceptable range is to , so is valid.
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42A capacitor marked is connected to a circuit. Which interpretation is correct?
Familiarization of electronic components
Hard
A. with tolerance
B. with tolerance
C. with tolerance
D. with tolerance
Correct Answer: with tolerance
Explanation:
The code 104 means . The letter J denotes a tolerance.
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43A polarized electrolytic capacitor is installed across a DC supply with its negative terminal connected to the positive rail. What is the most likely consequence?
Familiarization of electronic components
Hard
A.A permanent increase in dielectric strength
B.Improved ripple filtering at higher frequency
C.Reduced capacitance with no other effect
D.Increased leakage and possible capacitor failure
Correct Answer: Increased leakage and possible capacitor failure
Explanation:
Reverse voltage increases leakage current and can produce heating, venting, or rupture. Polarized capacitors must be connected with the correct polarity.
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44An LED and a resistor are connected in series to a supply. Assuming an LED forward drop of , which current is closest to the expected value?
Familiarization of electronic components
Hard
A.
B.
C.
D.
Correct Answer:
Explanation:
The resistor voltage is . Therefore, .
Incorrect! Try again.
45A diode is tested using a digital multimeter in diode mode. It reads approximately in one direction and displays an open-circuit indication in the other. What does this most strongly indicate?
Familiarization of electronic components
Hard
A.A shorted silicon diode junction
B.A reverse-biased germanium diode
C.An open diode junction in both directions
D.A normally functioning silicon diode
Correct Answer: A normally functioning silicon diode
Explanation:
A silicon diode typically shows a forward drop near to and blocks current in reverse when tested at low voltage.
Incorrect! Try again.
46A transistor's data sheet identifies its terminals as , , and , but the physical package orientation is unknown. Which method is safest for identifying the terminals before circuit connection?
Familiarization of electronic components
Hard
A.Connect the supply and identify terminals by heating
B.Use the data sheet and verify junctions with diode tests
C.Assume the center lead is always the base
D.Use resistance mode between every pair only
Correct Answer: Use the data sheet and verify junctions with diode tests
Explanation:
Package pinouts vary between transistor types. The data sheet provides the intended assignment, while diode-mode tests can verify the base-emitter and base-collector junction behavior.
Incorrect! Try again.
47A Zener diode is connected in reverse bias with a suitable series resistor. The supply is increased from to . Which behavior is expected if the current remains within its rated limits?
Familiarization of electronic components
Hard
A.The Zener current remains exactly unchanged
B.The Zener voltage becomes approximately twice as large
C.The Zener behaves as a forward-biased LED
D.The Zener voltage remains approximately constant
Correct Answer: The Zener voltage remains approximately constant
Explanation:
In the breakdown region, a Zener diode maintains an approximately constant voltage while the series resistor absorbs the increase in supply voltage as increased current.
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48A pushbutton input to a digital circuit changes unpredictably between logic states when pressed. Which component arrangement most directly addresses the problem?
Familiarization of electronic components
Hard
A.A fuse inserted in series with the input
B.A larger LED connected across the input
C.A pull-up or pull-down resistor with switch debouncing
D.A reverse-biased diode placed across the supply
Correct Answer: A pull-up or pull-down resistor with switch debouncing
Explanation:
The resistor prevents a floating input, while debouncing suppresses rapid mechanical transitions that can create multiple unintended logic edges.
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49Two resistors are marked and . Which connection produces an equivalent resistance of approximately ?
Familiarization of electronic components
Hard
A.Connection across the same wire
B.Parallel connection
C.Connection with one resistor open
D.Series connection
Correct Answer: Parallel connection
Explanation:
For parallel resistors, .
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50Before wiring a digital trainer circuit, the supply is set to the required voltage. Which additional practice best reduces the risk of damaging an integrated circuit?
Familiarization of the digital trainer module
Hard
A.Short unused IC inputs to the positive rail
B.Verify polarity and current-limit settings before insertion
C.Insert the IC while the trainer output is enabled
D.Increase the supply voltage to improve noise immunity
Correct Answer: Verify polarity and current-limit settings before insertion
Explanation:
Correct polarity and a conservative current limit protect the IC from wiring errors and excessive current during initial power-up.
Incorrect! Try again.
51A logic trainer's LED output indicator remains off when the measured output voltage is . Which diagnosis is most reasonable?
Familiarization of the digital trainer module
Hard
A.The output voltage proves the LED is open-circuit
B.The logic output is definitely at binary zero
C.The indicator may be active-low or incorrectly referenced
D.The IC must be operating without any supply voltage
Correct Answer: The indicator may be active-low or incorrectly referenced
Explanation:
An LED indicator may illuminate for a low output or use a different reference point. The actual logic level should be verified at the IC pin relative to the trainer ground.
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52A digital trainer provides a clock generator and a manual pulse switch. A counter advances several times for one manual press. What is the most likely cause?
Familiarization of the digital trainer module
Hard
A.The supply voltage is necessarily below the logic threshold
B.The counter has converted binary data into analog data
A mechanical switch can produce several rapid transitions during one press. A debouncing circuit or a conditioned one-shot pulse is required for reliable manual clocking.
Incorrect! Try again.
53A trainer module contains several unused inputs on a logic gate IC. Why should these inputs generally be assigned a defined logic level?
Familiarization of the digital trainer module
Hard
A.Defined inputs convert the gate into an analog amplifier
B.Floating inputs always force the output permanently low
C.Unused inputs automatically increase the output drive current
D.Floating inputs can respond to noise and cause unstable operation
Correct Answer: Floating inputs can respond to noise and cause unstable operation
Explanation:
Unconnected inputs may assume unpredictable voltages because of noise and leakage. Tying them to an allowed logic level produces predictable behavior.
Incorrect! Try again.
54A trainer uses a common-ground digital supply. An oscilloscope probe is connected with its ground clip to a signal point rather than circuit ground. What is the primary risk?
Familiarization of the digital trainer module
Hard
A.The displayed waveform will automatically double in frequency
B.The probe ground may short the signal to earth or circuit ground
C.The probe will convert the signal into a differential measurement
D.The circuit will become immune to ground noise
Correct Answer: The probe ground may short the signal to earth or circuit ground
Explanation:
Most bench oscilloscope ground clips are connected to protective earth. Attaching one to a non-ground signal can create a short circuit and damage the circuit or equipment.
Incorrect! Try again.
55A logic trainer's regulated output is correct with no load but drops significantly when an IC circuit is connected. Which check should be performed first?
Familiarization of the digital trainer module
Hard
A.Increase the regulated voltage above the IC rating
B.Disconnect the ground to remove loading
C.Replace every resistor with a lower resistance
D.Inspect for wiring errors or an unintended short circuit
Correct Answer: Inspect for wiring errors or an unintended short circuit
Explanation:
A large voltage drop under load commonly indicates excessive current caused by a short, reversed connection, or incorrectly inserted IC. Raising the voltage could worsen the damage.
Incorrect! Try again.
56A function generator is set to produce a sine wave with a DC offset. What are the maximum and minimum voltages relative to ground?
Familiarization of input sources and display devices related to electronic circuits
Hard
A. and
B. and
C. and
D. and
Correct Answer: and
Explanation:
A waveform has a peak amplitude of . Adding a offset gives maximum and minimum.
Incorrect! Try again.
57A function generator has a output and is connected to a high-impedance oscilloscope input. The generator display is calibrated for a load. What reading will commonly appear on the oscilloscope?
Familiarization of input sources and display devices related to electronic circuits
Hard
A.Approximately the same amplitude with reversed polarity
B.Approximately one-quarter the displayed amplitude
C.Approximately twice the displayed amplitude
D.Approximately half the displayed amplitude
Correct Answer: Approximately twice the displayed amplitude
Explanation:
The generator's internal resistance forms a divider with a matched load. A high-impedance scope removes that divider, so the measured open-circuit amplitude is commonly about twice the 50-ohm setting.
Incorrect! Try again.
58An oscilloscope displays a stable waveform only when its trigger level is set near the waveform's midpoint. What does this setting primarily control?
Familiarization of input sources and display devices related to electronic circuits
Hard
A.The voltage threshold at which sweep acquisition begins
B.The frequency generated by the signal source
C.The input impedance selected by the probe
D.The vertical scale used to measure waveform amplitude
Correct Answer: The voltage threshold at which sweep acquisition begins
Explanation:
The trigger level defines the signal voltage at which the oscilloscope starts each horizontal sweep, allowing repetitive waveforms to appear stationary.
Incorrect! Try again.
59A seven-segment display is connected to a decoder whose outputs are active-low. The display segments illuminate only when their cathodes are driven low. Which display type is compatible?
Familiarization of input sources and display devices related to electronic circuits
Hard
A.Differential-output display
B.Common-anode display
C.Common-cathode display
D.Open-collector sensor display
Correct Answer: Common-anode display
Explanation:
In a common-anode display, the anodes share the positive supply and individual segments turn on when their cathodes are pulled low by active-low outputs.
Incorrect! Try again.
60A digital circuit drives an LED directly from a logic output. The LED is brighter than expected and the IC becomes warm. Which change is most appropriate?
Familiarization of input sources and display devices related to electronic circuits
Hard
A.Connect the LED directly across the supply rails
B.Increase the logic output voltage above its rating
C.Remove the LED's polarity check from the circuit
D.Add a correctly sized series current-limiting resistor
Correct Answer: Add a correctly sized series current-limiting resistor
Explanation:
An LED requires current limiting. Without a suitable series resistor, excessive current can damage both the LED and the logic output driver.
Incorrect! Try again.
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