ATT TEST 8 EXAM LATEST 2024 ACTUAL EXAM QUESTIONS
AND CORRECT DETAILED ANSWERS WITH RATIONALES
(VERIFIED ANSWERS) |GRADED A+
In parallel voltage regulator, V out decreases when what happens? - ANSWER:
When DC input decreases or load current increases
What makes a zener diode different from junction diode? - ANSWER: Zener diode
is designed operate in breakdown
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 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
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: Q1
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 Q1
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
, In a voltage regulator, which component maintains a constant V out? - ANSWER:
Q1
In a voltage regulator, which components set voltage? - ANSWER: D1 and Q2
What does R2 do in voltage regulator? - ANSWER: Varies conduction of Q2
(changes Vce)
If input voltage increases in voltage regulator, Q2 must do what to maintain
constant output? - ANSWER: Increase resistance to drop more voltage (voltage of
Q2 increase)
What are 5 parts of a power supply? - ANSWER: Input, rectifier, filter, regulator,
protection
Which two parts of a power supply are optional? - ANSWER: Regulator and
protection
What is the purpose of a power supply? - ANSWER: To convert AC power into
smooth DC power
What does the input of a power supply do? - ANSWER: Step up or down the AC
input voltage
What does the rectifier do in a power supply? - ANSWER: Changes AC into
pulsating DC
What does the filter do in a power supply? - ANSWER: Changes pulsating DC into
smooth DC
How type of components do filters use? - ANSWER: Reactive components
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
The half wave rectifier is the same as what circuit? - ANSWER: Series limiter
AND CORRECT DETAILED ANSWERS WITH RATIONALES
(VERIFIED ANSWERS) |GRADED A+
In parallel voltage regulator, V out decreases when what happens? - ANSWER:
When DC input decreases or load current increases
What makes a zener diode different from junction diode? - ANSWER: Zener diode
is designed operate in breakdown
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 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
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: Q1
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 Q1
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
, In a voltage regulator, which component maintains a constant V out? - ANSWER:
Q1
In a voltage regulator, which components set voltage? - ANSWER: D1 and Q2
What does R2 do in voltage regulator? - ANSWER: Varies conduction of Q2
(changes Vce)
If input voltage increases in voltage regulator, Q2 must do what to maintain
constant output? - ANSWER: Increase resistance to drop more voltage (voltage of
Q2 increase)
What are 5 parts of a power supply? - ANSWER: Input, rectifier, filter, regulator,
protection
Which two parts of a power supply are optional? - ANSWER: Regulator and
protection
What is the purpose of a power supply? - ANSWER: To convert AC power into
smooth DC power
What does the input of a power supply do? - ANSWER: Step up or down the AC
input voltage
What does the rectifier do in a power supply? - ANSWER: Changes AC into
pulsating DC
What does the filter do in a power supply? - ANSWER: Changes pulsating DC into
smooth DC
How type of components do filters use? - ANSWER: Reactive components
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
The half wave rectifier is the same as what circuit? - ANSWER: Series limiter
