# Different Types of Multivibrators – 2 MCQ’s

This set of Analog Electronic Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Different Types of Multivibrators – 2″.

1. For the given circuit, find the time period of the output waveform, given that the diode is used is of Silicon and the supply voltage being applied is ±15V. The feedback factor is 0.4.

a) 11.12 ms
b) 12.4 ms
c) 11.2 seconds
d) 5.6 ms

2. Find the approximate frequency of output waveform of a monostable multivibrator given that RC = 20×10-3 and feedback factor = 0.3.
a) 200Hz
b) 142Hz
c) 233Hz
d) Can’t be found out without supply voltage value

3. Given the following circuit.

The supply voltage being applied is ±15V. The diode cut-in voltage is 0.7V. Find the maximum value of R such that circuit can behave as a monostable multivibrator.
a) 612.8kΩ
b) 33kΩ
c) 220.22kΩ
d) 450.8kΩ

4. Consider the circuit shown below.

R1=5kΩ, R2=5kΩ, R3=5kΩ, R4=10kΩ, R5=20kΩ, C1=10μF. Calculate the total charging time and discharging time.
a) The charging time = 0.2 seconds, the is charging time is 0.2 seconds
b) The charging time = 0.3 seconds, the discharging time is 0.2 seconds
c) The charging time = 0.3 seconds, the discharging time is 0.3 seconds
d) The charging time = 0.5 seconds, the discharging time is 0.4 seconds

5. What is the output frequency for the following circuit?

R4=30kΩ, R5=40kΩ, C1=5nF.
a) 2.63 kHz
b) 3kHz
c) 263 kHz
d) 4.4 kHz

6. How can a monostable multivibrator using IC 555 be used as a PWM generator?
a) If a diode is connected across the resistor RA
b) If a modulating signal m(t) is applied at the control pin
c) If the control pin is always kept high
d) It cannot be used as a PWM generator ever

7. For the given circuit, find the duty cycle of the output.

R4=30kΩ, R5=25kΩ.
a) 0.6875
b) 0.7211
c) 0.5681
d) 0.5010

8. In the astable multivibrator using IC 555, it can be used as a voltage to frequency converter.
a) True
b) False

9. Given that the charging current of capacitor is constant in a monostable multivibrator using IC 555, then find the type of output waveform, type of capacitor voltage waveform and the time period of output.
a) The capacitor waveform is a ramp, the output waveform is sinusoidal, the time period is 2.C.VCC3.I
b) The capacitor waveform is a ramp, the output waveform is a pulse, the time period is 2.C.VCC3.I
c) The capacitor waveform is a ramp, the output waveform is a pulse, the time period is C.VCC3.I
d) The capacitor waveform is a ramp, the output waveform is a ramp, the time period is 2.C.VCC3.I