ATT Test 8 Questions with correct
Answers
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
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 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 full wave 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
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
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 R1
If load current increases or DC input decreases, what needs to be done to maintain
constant level of V out (series voltage regulator)? - Answer- Increase R1 resistance to
decreases voltage drop on R1
What is the purpose of parallel voltage regulator? - Answer- Adjust current flow to
maintain V out at constant level
In parallel voltage regulator, V out increases when what happens? - Answer- DC input
increases or load current decreases
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
Answers
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
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 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 full wave 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
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
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 R1
If load current increases or DC input decreases, what needs to be done to maintain
constant level of V out (series voltage regulator)? - Answer- Increase R1 resistance to
decreases voltage drop on R1
What is the purpose of parallel voltage regulator? - Answer- Adjust current flow to
maintain V out at constant level
In parallel voltage regulator, V out increases when what happens? - Answer- DC input
increases or load current decreases
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
