ATT Test 7 Actual Exam Complete Questions with Correct
Answers (Verified Answers) Already Graded A+2025
What is the purpose of multivibrators? -Correct Answer ✔Convert DC ENERGY into
SQUARE WAVE ENERGY
How are transistors biased in multivibrators? -Correct Answer ✔To be in EITHER
saturation or cutoff, NEVER inbetween
What component determines which transistor is ON or OFF in multivibe circuit? -Correct
Answer ✔Feedback circuit
What does it mean when a transistor is ON? How many volts on collector? -Correct
Answer ✔Saturation (MAX current flow), 0 V
What does it mean when a transistor is OFF? How many volts on collector? -Correct
Answer ✔Cutoff (no current flow), 12 V
If both transistors have outputs (multivibe), what is phase shift between them? -Correct
Answer ✔180
Which type of multivibe circuit is free running? -Correct Answer ✔Astable
What components are in feedback circuit (Astable)? -Correct Answer ✔Two capacitors
What components are in feedback circuit (monostable)? -Correct Answer ✔One
capacitors and one resistor
What components are in feedback circuit (bistable)? -Correct Answer ✔Two capacitors,
two resistors
How is output determined in astable multivibe? -Correct Answer ✔Determined by
feedback circuit
Which transistor conducts first in astable multivibe? -Correct Answer ✔Whichever
reaches 0.6V first (Vcc applied, pos volts on Q1/Q2 base)
With Q1 ON (0v), how is Q2 turned off? (Astable) -Correct Answer ✔C1 discharging
puts negative charge to Q2 base
With Q1 ON (0V), how is Q2 turned ON? (Astable) -Correct Answer ✔C1 charging
increases volts Q2 base
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With Q2 ON (0V), how is Q1 turned OFF? (Astable) -Correct Answer ✔C2 discharging
puts negative charge to Q1 base
With Q2 ON (0V), how is Q1 turned ON? (Astable) -Correct Answer ✔C2 charging
increases volts Q1 base
What is another name for monostable multivibe? -Correct Answer ✔One Shot
How is frequency determined in monostable multivibe? -Correct Answer ✔Output
frequency = Input frequency
How is Q1 turned on (monostable)? -Correct Answer ✔Input pulse forward biases D1
and is applied to Q1 base
What happens when Q1 turns on (monostable)? -Correct Answer ✔C1 discharges and
turns OFF Q2 (12V)
When Q1 is ON, what causes it to turn OFF? (monostable) -Correct Answer ✔C1
charges enough to turn Q2 ON which turns Q1 off
How is frequency determined in bistable multivibes? -Correct Answer ✔Output
frequency is 1/2 Input frequency
If Q1 conducts first (ON 0V), how is Q2 turned OFF? (bistable) -Correct Answer
✔Negative volts on Q2 base coupled through capacitor
With Q1 ON, how is Q1 turned OFF? (Bistable) -Correct Answer ✔Negative pulse from
INPUT forward biases D1, negative signal turns Q1 OFF
With Q1 OFF, how is Q2 turned ON? (Bistable) -Correct Answer ✔!2V on Q1 collector
coupled to Q2 base by capacitor
What is troubleshooting procedure for astable multivibes? -Correct Answer ✔Check
output, Vcc, transistors, resistance checks
What is troubleshooting procedure for monostable/bistable multivibes? -Correct Answer
✔Check output, input trigger, Vcc, transistors, resistances
What is the purpose of a schmitt trigger? -Correct Answer ✔Convert ANY shape
waveform into square wave pulses of CONSTANT amplitude
Schmitt trigger is also called what other names? -Correct Answer ✔Squaring amp, level
detector, threshold detector
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