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ATT TEST 8 EXAM LATEST 2024 ACTUAL EXAM 200
QUESTIONS AND CORRECT DETAILED ANSWERS WITH
RATIONALES (VERIFIED ANSWERS) |ALREADY GRADED A
What does a regulator do in a power supply? - answer-maintains the output voltage at a constant level despite changes in load current What does a regulator do in a power supply? - answer-maintains the output voltage at a constant level despite changes in load current What does the protection circuit do in power supply? - answer-Prevents damage to power supply if load becomes faulty, limits or disables output What does the protection circuit do in power supply? - answer-Prevents damage to power supply if load becomes faulty, limits or disables output The half wave rectifier is the same as what circuit? - answer-Series limiter Which rectifier is the least efficient using only half the input? - answer-Half-wave Which two rectifiers require two input signals 180 degrees out of phase? - answer-Full-wave and bridge Which two rectifiers require two input signals 180 degrees out of phase? - answer-Full-wave and bridge Which rectifier uses a center tapped transformer? - answer-Full wave Which rectifier uses a center tapped transformer? - answer-Full wave How is frequency determined for half wave rectifier? - answer-Output frequency is same as input frequency
How is frequency determined for half wave rectifier? - answer-Output frequency is same as input frequency How is frequency determined for full wave rectifier? - answer-Output is twice the input frequency How is frequency determined for full wave rectifier? - answer-Output is twice the input frequency How is frequency determined for bridge rectifier? - answer-Output is twice the input frequency How is frequency determined for bridge rectifier? - answer-Output is twice the input frequency What is the purpose of series voltage regulators? - answer-To adjust voltage drop to maintain V out at constant level What is the purpose of series voltage regulators? - answer-To adjust voltage drop to maintain V out at constant level In a series voltage regulator, V out INCREASES when what happens? - answer-Load current decreases OR DC input increases In a series voltage regulator, V out INCREASES when what happens? - answer-Load current decreases OR DC input increases In series voltage regulator, V out DECREASES when what happens? - answer-Load current increases OR DC input decreases In series voltage regulator, V out DECREASES when what happens? - answer-Load current increases OR DC input decreases If load current decreases or DC input increases, what needs to be done to maintain constant level of V out (series volt regulator)? - answer-Increase R1 resistance to increase voltage drop on R
When does zener diode conduct reverse current? - answer-When reverse bias voltage is HIGHER than Vz (diode acts like resistor) When does zener diode conduct reverse current? - answer-When reverse bias voltage is HIGHER than Vz (diode acts like resistor) When diode is forward biased, what is the output voltage in shunt regulator? - answer-0.7V When diode is forward biased, what is the output voltage in shunt regulator? - answer-0.7V When reverse biased lower than Vz, what happens to zener diode? - answer-Acts like an open When reverse biased lower than Vz, what happens to zener diode? - answer-Acts like an open If reverse biased lower than Vz, what is output voltage of shunt regulator? - answer-Output is applied voltage If reverse biased lower than Vz, what is output voltage of shunt regulator? - answer-Output is applied voltage When reverse biased higher than Vz, what is the output voltage of shunt regulator? - answer-Vz When reverse biased higher than Vz, what is the output voltage of shunt regulator? - answer-Vz Which component changes resistances to maintain constant V out (zener diode regulator)? - answer-Q Which component changes resistances to maintain constant V out (zener diode regulator)? - answer-Q Which component sets output voltage (zener diode regulator)? - answer-D1 (holds Q1 at Vz)
Which component sets output voltage (zener diode regulator)? - answer-D1 (holds Q1 at Vz) The voltage on emitter is established by what in zener diode regulator? - answer-Action of Q The voltage on emitter is established by what in zener diode regulator? - answer-Action of Q If voltage increases what must happen to keep output voltage constant (zener diode regulator)? - answer-Q1 collector-emitter resistance must increase If voltage increases what must happen to keep output voltage constant (zener diode regulator)? - answer-Q1 collector-emitter resistance must increase If voltage decreases what must happen to keep output voltage constant (zener diode regulator)? - answer-Q1 collector-emitter resistance must decrease If voltage decreases what must happen to keep output voltage constant (zener diode regulator)? - answer-Q1 collector-emitter resistance must decrease In a voltage regulator, which component maintains a constant V out? - answer-Q In a voltage regulator, which component maintains a constant V out? - answer-Q In a voltage regulator, which components set voltage? - answer-D1 and Q In a voltage regulator, which components set voltage? - answer-D1 and Q What does R2 do in voltage regulator? - answer-Varies conduction of Q2 (changes Vce) What does R2 do in voltage regulator? - answer-Varies conduction of Q2 (changes Vce)
If load current increases in voltage regulator, what needs to be done to maintain constant output? - answer-Decrease resistance to drop less volts What two conditions cause Vout to INCREASE in voltage regulator? - answer-Input voltage increases or load current decreases What two conditions cause Vout to INCREASE in voltage regulator? - answer-Input voltage increases or load current decreases What two conditions cause Vout to DECREASE in voltage regulator? - answer-Input voltage decreases or load current increases What two conditions cause Vout to DECREASE in voltage regulator? - answer-Input voltage decreases or load current increases What are the most common faults in voltage regulators? - answer-Semiconductor components (transistors/diodes) What are the most common faults in voltage regulators? - answer-Semiconductor components (transistors/diodes) In a zener diode regulator, which faults cause output voltage to approach applied voltage? - answer-D open, Short between Collector-Emitter In a zener diode regulator, which faults cause output voltage to approach applied voltage? - answer-D open, Short between Collector-Emitter In zener diode regulator, which faults cause output voltage to be 0V? - answer-D1 short/R1 Open, open between Base-Emitter In zener diode regulator, which faults cause output voltage to be 0V? - answer-D1 short/R1 Open, open between Base-Emitter
Which fault in zener diode regulation can damage diode? - answer-R1 short Which fault in zener diode regulation can damage diode? - answer-R1 short How do you calculate base voltage of Q1 in voltage regulator? - answer-Vz + Vce = Vb How do you calculate base voltage of Q1 in voltage regulator? - answer-Vz + Vce = Vb Which fault in zener diode /voltage regulator causes Q1 base voltage to increase and approach saturation? - answer-D1 Open Which fault in zener diode /voltage regulator causes Q1 base voltage to increase and approach saturation? - answer-D1 Open Which fault in zener diode / voltage regulator causes Q1 base voltage to decreases and approach cutoff?
- answer-D1 short (no output volts) Which fault in zener diode / voltage regulator causes Q1 base voltage to decreases and approach cutoff?
- answer-D1 short (no output volts) Which faults cause output voltage to approach applied volts in voltage regulator? - answer-D1 open, R short, Q1 short Collector-Emitter Which faults cause output voltage to approach applied volts in voltage regulator? - answer-D1 open, R short, Q1 short Collector-Emitter Which faults cause output voltage to be 0V in voltage regulator? - answer-R1 open, open Q1 base- emitter Which faults cause output voltage to be 0V in voltage regulator? - answer-R1 open, open Q1 base- emitter
When is unijunction transistor on? - answer-When current flows from emitter to base 1 How is turn on voltage determined unijunction transistor? - answer-Eta times Vcc How is turn on voltage determined unijunction transistor? - answer-Eta times Vcc What is the purpose of silicon control rectifier? - answer-Switch current on and off, turns on when current is applied to gate What is the purpose of silicon control rectifier? - answer-Switch current on and off, turns on when current is applied to gate The gate is attached to which part of diode in SCR? - answer-Cathode The gate is attached to which part of diode in SCR? - answer-Cathode What type of material is gate in SCR? - answer-Very thin p-type material What type of material is gate in SCR? - answer-Very thin p-type material When will current flow in SCR? - answer-When diode is forward biased AND positive current flow is attached to gate When will current flow in SCR? - answer-When diode is forward biased AND positive current flow is attached to gate What happens when gate current is removed in SCR? - answer-Nothing, diode is latched on What happens when gate current is removed in SCR? - answer-Nothing, diode is latched on
How is SCR turned off? - answer-Current flow must be interrupted with switch or by shorting anode to cathode How is SCR turned off? - answer-Current flow must be interrupted with switch or by shorting anode to cathode What is the range of trigger currents in SCR? - answer-2mA to 20mA What is the range of trigger currents in SCR? - answer-2mA to 20mA What is a purpose of relays? - answer-Used for applying power to circuits or controlling signal flow What is a purpose of relays? - answer-Used for applying power to circuits or controlling signal flow What are two benefits of relays? - answer-Can handle higher levels of current, make large power transfers possible What are two benefits of relays? - answer-Can handle higher levels of current, make large power transfers possible How are relays shown on schematics? - answer-De-Energized How are relays shown on schematics? - answer-De-Energized Saying contacts are normally closed or normally open refers to them in which state? - answer-De- energized Saying contacts are normally closed or normally open refers to them in which state? - answer-De- energized
What is used to fix burned contacts? - answer-Burnishing tool What is TS procedure for relays? - answer-Check inputs, check outputs What is TS procedure for relays? - answer-Check inputs, check outputs What is TS procedure for electrical circuits? - answer-Analyze, check setup, calculate/measure, check results What is TS procedure for electrical circuits? - answer-Analyze, check setup, calculate/measure, check results What are most common faults in electrical circuits? - answer-Open/short What are most common faults in electrical circuits? - answer-Open/short If a diode is shorted in power supply what happens? - answer-LED wont illuminate, AC isnt converted to DC If a diode is shorted in power supply what happens? - answer-LED wont illuminate, AC isnt converted to DC If diode is open in power supply what happens? - answer-LED wont illuminate, pulsating DC missing cycle If diode is open in power supply what happens? - answer-LED wont illuminate, pulsating DC missing cycle What are three circuits in an op amp? - answer-Differential amp, common collector amp, push pull amp What are three circuits in an op amp? - answer-Differential amp, common collector amp, push pull amp
What is the purpose of op amps? - answer-Use two inputs to determine an output (versatile, replace transistors) What is the purpose of op amps? - answer-Use two inputs to determine an output (versatile, replace transistors) What does + indicate on op amp? - answer-Non-inverting What does + indicate on op amp? - answer-Non-inverting What does - indicate on op amp? - answer-Inverting What does - indicate on op amp? - answer-Inverting Using both inputs produces what type of amp? - answer-Diffential Using both inputs produces what type of amp? - answer-Diffential Connecting several inputs to inverting (-) input produces which type of amp? - answer-Summing amp Connecting several inputs to inverting (-) input produces which type of amp? - answer-Summing amp How are op amps packaged? - answer-IC chip How are op amps packaged? - answer-IC chip Where does most of amplification happen in op amp? - answer-Pushpull amp
Electrical circuit - answer- Electrical circuit - answer- Electrical circuits - answer- Electrical circuits - answer-
