welcome to the 2023 ASVAB electronic information practice test this tests why 40 questions have explained answers that will help you prepare for the test be sure to boot that like button by turning it white now here's your advice instructor to walk you through the questions question one what is a transistor and how does it function in electronic circuits a a device that converts electrical energy into mechanical energy be a device that regulates the flow of current in an electric electronic circuit a a device that converts electrical energy into mechanical energy b a device that regulates the flow of current in an electronic circuit c a device that stores data in electronic devices d a device that converts mechanical energy into electrical energy the correct answer is b a device that regulates the flow of current in an electronic circuit transistors are semiconductor devices that can act as switches or amplifiers in electronic circuits they function by controlling the flow of current between two terminals allowing electronic devices to perform various functions such as amplification signal processing and switching question two what is the purpose of a capacitor in an electronic circuit and how does it store and release electrical energy a to regulate the flow of current in an electronic circuit B to store and release electrical energy in an electronic circuit C to convert electrical energy into mechanical energy D to amplify electrical signals in an electronic circuit the correct answer is B to store and release electrical energy in an electronic circuit capacitors are passive electronic components that can store electrical energy temporarily in an electric field they are commonly used in electronic circuits for filtering timing and energy storage purposes question three what is the difference between analog and digital signals and what are some common applications for each a analog signals are continuous while digital signals are discrete B analog signals are discrete while digital signals are continuous C both analog and digital signals are continuous D both analog and digital signals are discrete the correct answer is a analog signals are continuous while digital signals are discrete analog signals are continuous electrical signals that vary in magnitude over time while digital signals are discrete signals that represent information as binary code common applications of analog signals include audio and video transmission while digital signals are commonly used in digital communication data processing and computing question four what is a microprocessor and how does it process and store information in electronic devices a a device that amplifies electrical signals in an electronic circuit be a device that converts mechanical energy into electrical energy c a device that processes and stores information in electronic devices d a device that regulates the flow of current in an electronic circuit the correct answer is c a device that processes and stores information in electronic devices a microprocessor is a central processing unit CPU that controls and performs calculations in electronic devices it processes and stores information using digital circuits allowing electronic devices to perform a variety of functions such as data processing communication and control question 5 what is a function of a diode in an electronic circuit and how does it regulate the flow of current in One Direction a to store and release electrical energy in an electronic circuit B to convert mechanical energy into electrical energy C to amplify electrical signals in an electronic circuit D to regulate the flow of current in One Direction in an electronic circuit the correct answer is D to regulate the flow of current in One Direction in an electronic circuit a diode is a semiconductor device that allows current to flow in One Direction and blocks it in the other direction it functions as a one-way valve for electrical current allowing electronic devices to perform such functions as rectification voltage regulation and Signal modulation question six what is the difference between RAM and ROM memory in a computer system and what are some common uses of each types of memory a ram is read-only memory while ROM Is Random Access Memory B Ram is volatile while ROM is non-volatile C Ram stores data permanently while ROM stores data temporarily D Ram is slower than ROM the correct answer is B Ram is volatile while ROM is non-volatile Ram random access memory is a type of computer memory that can be accessed randomly and is used to temporarily store data that the CPU is actively using ROM read only memory on the other hand is a type of non-volatile memory that stores data permanently and is used to store critical system information and firmware that cannot be altered question 7 what is a logic gate and how does it process binary information in digital circuits a a device that amplifies electrical signals in an electronic circuit be a device that converts mechanical energy into electrical energy c a device that performs logical operations on binary data in a digital circuit d a device that regulates the flow of current in an electronic circuit the correct answer is c a device that performs logical operations on binary data in a digital circuit a logic gate is an electronic component that performs Boolean logic operations such as and or and not on binary data in digital circuits it processes binary information by controlling the flow of electrical signals between its input and output terminals question 8 what is the function of a transformer in an electronic circuit and how does it change voltage and current levels a to store and release electrical energy in an electronic circuit B to amplify electrical signals in an electronic circuit C to regulate the flow of current in an electronic circuit D to change voltage and current levels in an electronic circuit the correct answer is D to change voltage and current levels in an electronic circuit a Transformer is an electrical device that can increase or decrease the voltage and current levels of an alternating current AC signal it does this by using two coils of wire wrapped around a magnetic core to induce a voltage across the other coil question 9 what is a printed circuit board PCB and how does it provide a compact and reliable method for connecting electronic components in a circuit a a device that amplifies electrical signals in an electronic circuit b a device that converts mechanical energy into electrical energy see a board that supports and connects electronic components in a circuit d a device that regulates the flow of current in an electronic circuit the correct answer is c a board that supports and connects electronic components in a circuit a printed circuit board PCB is a flat board made of insulating material on which electronic components and circuits are mounted it provides a compact and reliable method for connecting electronic components in a circuit by using conductive tracks pads and Vias to established electrical connections between them question 10 what is the purpose of a voltage regulator in an electronic circuit and how does it maintain a stable output voltage despite changes in input voltage or load current a to store and release electrical energy in an electronic circuit B to amplify electrical signals in an electronic circuit C to regulate the flow of current in an electronic circuit D to maintain a stable output voltage despite changes in an input voltage or load current the correct answer is D to maintain a stable output voltage despite changes in input voltage or load current a voltage regulator is an electronic component that maintains a constant output voltage regardless of changes in the input voltage or load current it does this by using feedback to adjust the output voltage to a preset level providing a stable power supply to other electronic components in the circuit question 11 what is an operational amplifier op amp and how does it amplify and manipulate signals in electronic circuits a a type of digital signal processor used in audio applications B and electronic component that amplifies and processes analog signals see a type of multi-controller used in power management D an optical device used for switching and routing signals the correct answer is B an electronic component that amplifies and processes analog signals an operational amplifier op amp is an electronic component that amplifies and processes analog signals in electronic circuits op amps are widely used in various applications such as amplifiers filters and Signal generators they can be used to perform mathematical operations like addition subtraction multiplication and integration question 12 what is the difference between an AC alternating current and DC direct current power supply and what are some common applications of each type of power a AC power is used for high voltage applications while DC power is used for low voltage applications B AC power Flows In One Direction only while DC power flows in both directions C AC power changes Direction periodically while DC power Flows In One Direction DAC power is more efficient than DC power for most applications the correct answer is C AC power changes Direction periodically while DC power Flows In One Direction AC power is commonly used in household electrical outlets and power grids while DC power is often used in batteries and electronic devices such as computers and smartphones some common applications of AC power include electric motors lighting and heating systems while DC power is used in electronic devices and electric vehicles question 13 what is the function of a sensor in an electronic system and how does it convert physical parameters into electrical signals a a sensor amplifies electrical signals and sends them to a controller b a sensor converts electrical signals into physical parameters c a sensor detects physical parameters and converts them into electrical signals d a sensor filters out unwanted signals in an electronic system the correct answer is c a sensor detects physical parameters and converts them into electrical signals a sensor detects physical parameters such as temperature pressure or light and converts them into electrical signals that can be measured and processed by electronic systems the conversion process is based on various physical phenomena such as resistance capacitance or piezoelectricity sensors are used in many applications such as automation environmental monitoring and medical devices question 14 what is a flip-flop and how does it store and process binary information in digital circuits a a type of clock signal used in digital circuits b a type of logic gate used to perform arithmetic operations c a type of memory element used to store binary data d a type of voltage regulator used to stabilize power supply the correct answer is c a type of memory element used to store binary data a flip-flop is a type of memory element used to store binary data in digital circuits it can store a single bit of information and has two stable states which represent the two binary values zero and one flip-flops are used to build sequential logic circuits which process data based on its previous state and the current input question 15 what is the purpose of a filter in an electronic circuit and how does it attenuate or amplify certain frequencies of an input signal a a filter is used to generate a clock signal in digital circuits B A filter is used to measure the amplitude of an input signal see a filter is used to attenuate or amplify certain frequencies of an input signal d a filter is used to convert analog signals to digital signals the correct answer is c a filter is used to attenuate or amplify certain frequencies of an input signal the purpose of a filter in an electronic circuit is to attenuate or amplify certain frequencies of an input signal while letting other frequencies pass through unchanged filters can be used to remove unwanted noise improve sound quality or extract specific frequency components from a signal filters work by creating a frequency dependent impedance that selectively affects certain frequency components of the input signal question 16 what is the function of a voltage divider in an electronic circuit and how does it divide a voltage into smaller values a a voltage divider is used to amplify a voltage in an electronic circuit b a voltage divider is used to generate a clock signal in digital circuits see a voltage divider is used to divide voltage into smaller values d a voltage divider is used to convert analog signals to digital signals the correct answer is c a voltage divider is used to divide a voltage into smaller values the function of a voltage divider in an electronic circuit is to divide a voltage into smaller values a voltage divider consists of two resistors connected in series with the output voltage taken across one of the resistors the ratio of the two resistor values determines the amount by which the input voltage is divided question 17 what is a signal generator and how does it produce electrical signals of various frequencies and waveforms for testing electronic equipment a a device used to generate digital signals for use in digital circuits b a device used to generate power for electronic equipment see a device used to produce electrical signals of various frequencies and waveforms for testing electronic equipment d a device used to measure the frequency of an input signal the correct answer is c a device used to produce electrical signals of various frequencies and waveforms for testing electronic equipment a signal generator is a device used to produce electrical signals of various frequencies and waveforms for testing electronic equipment signal generators can produce sine waves square waves triangular waves and other waveforms with frequencies ranging from a few Hertz to several gigahertz they are commonly used in the design testing and troubleshooting of electronic circuits question 18 what is the function of a multiplexer in an electronic circuit and how does it select and combine multiple input signals into a single output signal a a multiplexer is used to generate a clock signal in digital circuits B A multiplexer is used to measure the amplitude of an input signal C A multiplexer is used to select and combine multiple input signals into a single output signal d a multiplexer is used to convert analog signals to digital signals the correct answer is c a multiplexer is used to select and combine multiple input signals into a single output signal the function of a multiplexer in an electronic circuit is to select and combine multiple input signals into a single output signal a multiplexer has multiple input channels and one output channel the output Channel selects one of the input channels based on a control signal and passes the selected input signal to the output multiplexers are used to Route Digital Data analog signals or both in a variety of electronic applications question 19 what is a logic analyzer and how does it capture and analyze digital signals in an electronic system for debugging and testing purposes a a device used to generate analog signals for testing electronic equipment b a device used to capture and analyze digital signals in an electronic system for debugging and testing purposes see a device used to measure the frequency of an input signal d a device used to generate power for electronic equipment the correct answer is b a device used to capture and analyze digital signals in an electronic system for debugging and testing purposes a logic analyzer is a device used to capture and analyze digital signals in an electronic system for debugging and testing purposes a logic analyzer can capture a large number of digital signals simultaneously and display them as waveforms it can also decode and analyze digital protocols detect glitches and timing errors and help troubleshoot digital systems question 20 what is the purpose of a power amplifier in an audio or radio frequency RF system and how does it amplify a low power signal to a higher power level for transmission or amplification a a power amplifier is used to generate a clock signal in digital circuits b a power amplifier is used to measure the amplitude of an input signal c a power amplifier is used to amplify a low power signal to a higher power level for transmission or amplification d a power amplifier is used to convert analog signals to digital signals the correct answer is c a power amplifier is used to amplify a low power signal to a high power level for transmission or amplification the purpose of a power amplifier in an audio or radio frequency RF system is to amplify a low power signal to a higher power level for transmission or amplification a power amplifier uses active devices such as transistors or tubes to increase the amplitude of the input signal while maintaining its waveform shape power amplifiers are used in a variety of applications such as audio systems radio transmitters and Wireless Communications question 21 what is the difference between a digital to analog converter DAC and an analog to digital converter ADC and what are some common applications of each type of converter a a DAC converts digital signals into analog signals while an ADC converts analog signals to digital signals dacs are used in audio systems and adcs are used in digital sensors b a DAC converts analog signals to digital signals while an ADC converts digital signals to analog signals dacs are used in digital sensors while adcs are used in audio systems c a DAC and an ADC are the same thing but can be used interchangeably in electronic systems d a DAC converts digital signals to analog signals and an ADC converts analog signals to digital signals dacs are used in audio systems and electronic music instruments while adcs are used in digital sensors and data acquisition systems the correct answer is d a DAC converts digital signals to analog signals while an ADC converts analog signals to digital signals dacs are used in audio systems and electronic music instruments while adcs are used in digital sensors and data acquisition systems the main difference between a digital to analog converter DAC and an analog to digital converter ADC is the direction of signal conversion a DAC converts digital signals to analog signals while an ADC converts analog signals to digital signals dacs are used in a variety of applications such as audio systems electronic music instruments and waveform generators adcs are used in digital sensors data acquisition systems and audio signal processing question 22 what is the function of a Field Effect transistor fet and how does it differ from a bipolar Junction transistor BJT a an fet is used to amplify analog signals while a BJT is used to amplify digital signals B and fet is a type of digital logic gate while a BJT is a type of analog amplifier C and fet controls the flow of current using an electric field while a BJT controls the flow of current using a bipolar Junction D and fet is faster than a BJT but has lower gain and higher noise the correct answer is C and fet controls the flow of current using an electric field while a BJT controls the flow of current using a bipolar Junction fets have a high input impedance and low output impedance making them ideal for applications where low power consumption and high impedance are important bjts have a lower input impedance and higher output impedance making them more suitable for applications that require High Gain and high current question 23 what is a Schmidt trigger and how does it provide hysteresis and noise immunity to a digital signal in an electronic circuit a a device used to measure the frequency of an input signal b a device used to generate clock signal in digital circuits c a device used to provide hysteresis and noise immunity to a digital signal in an electronic circuit d a device used to amplify a low power signal to a higher power level for transmission or amplification the correct answer is c a device used to provide hysteresis or noise immunity to a digital signal in an electronic circuit it converts a noisy or slowly varying input signal into a clean and well-defined output signal by adding positive feedback this results in a voltage level switching that is independent of the input Signal's rise or fall times question 24 what is the function of a phase-locked loop PPL and how does it synchronize the phase and frequency of an output signal with a reference signal a a PPL is used to generate clock signals for digital circuits B A PPL is used to measure the frequency of an input signal C A PPL is used to synchronize the phase and frequency of an output signal with a reference signal d a PPL is used to amplify a low power signal to a higher power level for transmission or amplification the correct answer is c a PPL is used to synchronize the phase and frequency of an output signal with a reference signal it compares the frequency and phase of the reference signal with the output signal and then adjusts the phase and frequency of the output signal to match the reference signal ppls are commonly used in communication systems audio and video equipment and frequency synthesizers question 25 what is a thyristor and how does it control the flow of current in an electronic circuit by switching between on and off States a a device used to measure the frequency of an input signal b a device used to generate a clock signal in digital circuits see a device used to control the flow of current in an electronic circuit by switching between on and off States d a device used to amplify a low power signal to a higher power level for transmission or amplification the correct answer is c a device used to control the flow of current in an electronic circuit by switching between on and off States it consists of three or four layers of semiconductor material and it can be triggered into conduction by a small current or voltage once triggered it will remain conducting until the current through it is reduced to zero question 26 what is the function of a voltage regulator module vrm and how does it regulate the voltage and current supplied to a microprocessor or other electronic component a a device used to amplify a low power signal to a higher power level for transmission or amplification b a device used to control the flow of current in an electronic circuit by switching between on and off States c a device used to measure the frequency of an input signal d a device used to regulate the voltage in current supplied to the microprocessor or other Electronic Component the correct answer is d a device used to regulate the voltage and current supplied to the microprocessor or other electronic component it converts a higher voltage from a power supply into a lower more stable voltage suitable for use by the component vrms are used in computers servers and other electronic devices to ensure reliable operation and prevent damage from voltage fluctuations 27 what is a transistor transistor logic TTL circuit and how does it provide fast switching speeds and low power consumption in digital systems a a device used to regulate the voltage and current supplied to a microprocessor or other electronic component b a type of logic circuit used in digital systems that uses transistors to provide fast switching speeds and low power consumption c a device used to control the flow of current in an electronic circuit by switching between on and off States d a device used to amplify a low power signal to a higher power level for transmission or amplification the correct answer is b a type of logic circuit used in digital systems that uses transistors to provide fast switching speeds and low power consumption TTL circuits are commonly used in microprocessors memory chips and other digital devices due to their high speed low power consumption and compatibility with a wide range of voltage levels they operate by using transistors to switch between two voltage levels representing logical one and zero question 28 what is the difference between a half wave rectifier and a full wave rectifier and what are some applications of each type of rectifier a a half wave rectifier rectifies only one half of the AC waveform while a full wave rectifier rectifies both halves b a full wave rectifier rectifies only one half of the AC waveform while the half wave rectifier rectifies both halves c a half wave rectifier rectifies both halves of the AC waveform while a full wave rectifier rectifies only one half d a full wave rectifier rectifies both halves of the AC waveform while a half wave rectifier rectifies only one half the correct answer is d a full wave rectifier rectifies both halves of the AC waveform while a half wave rectifier rectifies only one half a half wave rectifier is simpler and less expensive but provides only half the output voltage compared to a full wave rectifier full wave rectifiers are commonly used in power supplies battery chargers and DC motor speed controllers question 29 what is a crystal oscillator and how does it provide a stable frequency reference for electronic circuits and systems a a crystal oscillator is a type of microphone that converts sound waves into electrical signals b a crystal oscillator is a type of amplifier that boosts the signal strength of an electronic circuit c a crystal oscillator is an electronic circuit that uses the mechanical residence of a vibrating Crystal to generate a stable electrical signal d a crystal oscillator is a type of switch that controls the flow of current in an electronic circuit the correct answer is c a crystal oscillator is an electronic circuit that uses the mechanical Resonance of a vibrating Crystal to generate a stable electrical signal the crystal oscillator consists of a crystal and amplifier and a feedback circuit when a voltage is applied to the crystal it vibrates at a natural frequency and the feedback circuit ensures that the amplifier only amplifies the frequency of the crystal crystal oscillators are used in electronic devices that require precise and stable timing such as clocks watches and computer processors question 30 what is the function of a magnetic amplifier and how does it control the flow of current in an electronic circuit by varying the magnetic flux in a Transformer core a a magnetic amplifier is an electronic circuit that amplifies the strength of a magnetic field b a magnetic amplifier is a type of Transformer that increases the voltage of an AC signal c a magnetic amplifier is an electronic device that controls the flow of current in an electronic circuit by varying the magnetic flux in a Transformer core d a magnetic amplifier is a type of relay that switches on and off when a magnetic field is present the correct answer is c a magnetic amplifier is an electronic device that controls the flow of current in an electronic circuit by varying the magnetic flux in a Transformer core the magnetic amplifier consists of a transformer with a magnetic core and a control winding when a control current is applied to the control winding it varies the magnetic flux in the core which in turn controls the flow of current in the load winding magnetic amplifiers are used in power supplies motor speed controllers and other electronic circuits that require precise control of current note magnetic amplifiers are not currently used in modern Electronics as solid-state electronic devices have largely replaced them question 31 what is a voltage-controlled oscillator vco and how does it generate an output signal whose frequency can be varied by changing the input voltage a a vco is a device that generates a fixed frequency output signal and its frequency can be varied by changing the input voltage B A vco is a device that generates a variable frequency output signal and its frequency can be varied by changing the input current C of Eco is a device that generates a fixed frequency output signal and its frequency can be varied by changing the input current D of Eco is a device that generates a variable frequency output signal and its frequency can be varied by changing the input voltage the correct answer is d a vco is a device that generates a variable frequency output signal and its frequency can be varied by changing the input voltage a vco typically contains an oscillator circuit that produces a periodic waveform such as a sine wave or a square Wave by changing the input voltage the frequency of the output waveform can be changed vcos are commonly used in frequency modulation FM synthesis phase locked loops ppls and electronic musical instruments question 32 what is the difference between a jfet junction Field Effect transistor and a mosfet metal oxide semiconductor Field Effect transistor and what are some applications of each type of transistor a jfets are normally off devices while mosfets are normally on devices jfets are often used in audio amplifiers while mosfets are used in Power Electronics B J fets are normally on devices while mosfets are normally off devices jfets are often used in Power Electronics while mosfets are used in audio amplifiers C J fats and mosfets are both normally on devices jfets are often used in Power Electronics while mosfets are used in audio amplifiers D J fats and mosfets are both normally off devices jfets are often used in audio amplifiers while mosfets are used in Power Electronics the correct answer is a j fats are normally off devices while mosfets are normally on devices jfets are often used in audio amplifiers while mosfets are used in Power Electronics the main difference between jfets and mosfets is the way they are constructed and the way they operate jfets have a channel formed by a semiconductor Junction while mosfets have a channel formed by a layer of oxide jfets are often used in low noise amplifiers and as switches in electronic circuits while mosfets are commonly used in Power Electronics such as power supplies and motor control circuits question 33 what is a digital signal processor DSP and how does it process and manipulate digital signals in electronic systems a a DSP is a device that converts analog signals to digital signals it uses software algorithms to perform mathematical operations on the digital signals b a DSP is a device that converts digital signals to analog signals it uses Hardware circuits to perform mathematical operations on the digital signals c a DSP is a device that performs mathematical operations on digital signals it can be used for Signal filtering modulation demodulation and other signal processing tasks d a DSP is a device that performs mathematical operations on analog signals it can be used for Signal filtering modulation demodulation and other signal processing tasks the correct answer is c a DSP is a device that performs mathematical operations on digital signals it can be used for Signal filtering modulation demodulation and other signal processing tasks a DSP typically includes a microprocessor or a specialized Digital Signal processing chip along with software and Hardware circuits designed to process digital signals dsps are used in a wide range of applications including audio processing video processing communication systems and control systems question 34 what is the function of our frequency counter and how does it measure the frequency of an input signal in an electronic circuit or system a a frequency counter is a device that measures the amplitude of an input signal in an electronic circuit or system b a frequency counter is a device that measures the phase shift of an input signal in an electronic circuit or system c a frequency counter is a device that measures the frequency of an input signal in electronic circuit or system d a frequency counter is a device that measures the noise level of an input signal in an electronic circuit or system the correct answer is c a frequency counter is a device that measures the frequency of an input signal in an electronic circuit or system a frequency counter typically includes a timer or a counter circuit that measures the time between successive cycles of the input signal by counting the number of Cycles within a given time period the frequency of the input signal can be determined frequency counters are commonly used in electronic test and measurement equipment such as oscilloscopes function generators and Signal generators question 35 what is a voltage-controlled filter VCF and how does it attenuate or amplify certain frequencies of an input signal by varying the cutoff frequency a a VCF is a device that amplifies the input signal by varying the cutoff frequency b a VCF is a device that attenuates the input signal by varying the cutoff frequency of ECF is a device that filters out high frequency signals by varying the cutoff frequency D of ECF is a device that filters out low frequency signals by varying the cutoff frequency the correct answer is b a VCF is a device that attenuates the input signal by varying the cutoff frequency a VCF typically includes a filter circuit that selectively passes or blocks certain frequencies of the input signal by varying the cutoff frequency of the filter circuit using a voltage controlled resistor or capacitor the amplitude of the filtered signal can be controlled vcfs are commonly used in electronic music synthesizers and other audio applications to create various filtering effects question 36 what is a digital potentiometer and how does it provide a variable resistance in an electronic circuit a a digital potentiometer is a device that provides a fixed resistance value in an electronic circuit b a digital potentiometer is a device that provides a variable resistance value in an electronic circuit see a digital potentiometer is a device that provides a fixed voltage value in an electronic circuit d a digital potentiometer is a device that provides a variable voltage value in an electronic circuit a a digital potentiometer is a device that provides a fixed resistance value in an electronic circuit b a digital potentiometer is a device that provides a variable resistance value in an electronic circuit see a digital potentiometer is a device that provides a fixed voltage value in an electronic circuit d a digital potentiometer is a device that provides a variable voltage value in an electronic circuit the correct answer is b a digital potentiometer is a device that provides a variable resistance value in an electronic circuit a digital potentiometer typically consists of a series of resistive elements controlled by a digital input signal by varying the digital input signal the resistance value of the digital potentiometer can be adjusted digital potentiometers are commonly used in audio volume control motor control and other applications where precise and adjustable resistance values are required question 37 what is the function of a phase shifter and how does it delay or Advance the phase of an input signal in an electronic system a a phase shifter is a device that amplifies an input signal in an electronic system b a phase shifter is a device that filters out unwanted frequencies in an input signal in an electronic system see a phase shifter is a device that delays or advances the phase of an input signal in an electronic system d a phase shifter is a device that modulates the frequency of an input signal in an electronic system the correct answer is c a phase shifter is a device that delays or advances the phase of an input signal in an electronic system a phase shifter typically introduces a network of delay lines or all pass filters that introduce a variable phase shift to the input signal by controlling the phase shift the phase relationship between the input signal and other signals in the system can be adjusted phase shifters are commonly used in audio processing radar systems and other applications where precise control of the phase relationship between signals is required question 38 what is a photodiode and how does it convert light energy into electrical signals in an electronic circuit or system a a photodiode is a device that converts electrical energy into light energy in an electronic circuit b a photodiode is a device that generates electrical signals in response to changes in temperature in an electronic circuit c a photodiode is a device that converts light energy into electrical signals in an electronic circuit d a photodiode is a device that measures the intensity of the magnetic fields in an electronic circuit the correct answer is c a photodiode is a device that converts light energy into electrical signals in an electronic circuit photodiodes are made of a semiconductor material that absorbs photons of light and generates an electrical current in response the current generated by the photodiode is proportional to the intensity of the light that falls on it and can be used in electronic circuits to detect and measure light question 39 what is a comparator and how does it compare two input signals and produce an output signal based on their relative magnitudes in an electronic circuit a a comparator is a device that amplifies an input signal in an electronic circuit B A comparator is a device that filters out unwanted frequencies in an input signal in an electronic circuit C A comparator is a device that compares two input signals and produces an output signal based on the relative magnitudes in an electronic circuit d a comparator is a device that modulates the frequency of an input signal in an electronic circuit the correct answer is C A comparator is a device that compares two input signals and produces an output signal based on the relative magnitudes in an electronic circuit a comparator typically has two input terminals that are compared and an output terminal that produces a voltage or Digital Signal based on that comparison if the voltage on the non-inverting input is greater than the voltage on the inverting input the output voltage will be high if the voltage on the inverting input is greater the output voltage will be low comparators are commonly used in voltage level detection signal conditioning and other applications where signal comparison is required question 40. what is a band pass filter and how does it attenuate or amplify a range of frequencies centered around a certain frequency in an input signal a a band pass filter is a device that amplifies all frequencies in an input signal B A bandpass filter is a device that attenuates all frequencies in an input signal see a bandpass filter is a device that attenuates or amplifies a range of frequencies centered around a certain frequency in an input signal d a band pass filter is a device that modulates the frequency of an input signal in an electronic circuit the correct answer is c a band pass filter is a device that attenuates or amplifies a range of frequencies centered around a certain frequency in an input signal a bandpass filter typically consists of a combination of low-pass and high pass filters that allow a certain range of frequencies to pass through while attenuating frequencies outside that range the center frequency and bandwidth of the filter can be adjusted by varying the values of the filter components bandpass filters are commonly used in audio and radio frequency applications to select or reject specific frequency ranges thank you for watching this video we hope you enjoyed it check out these videos that can help you study for your ASVAB tests if you need more help Beyond these videos we have free practice tests on our website we have all the links down in the description below don't forget to boot that like button and subscribe to our Channel