In this section of Electronic Devices and Circuits.It contain Sinusoidal Oscillators MCQs (Multiple Choice Questions Answers).All the MCQs (Multiple Choice Question Answers) requires in depth reading of Electronic Devices and Circuits Subject as the hardness level of MCQs have been kept to advance level.These Sets of Questions are very helpful in Preparing for various Competitive Exams and University level Exams.

This Section covers below lists of topics :

1. Sinusoidal Oscillators MCQs.
2. Transistor Oscillators MCQs.
3. Tuned collector oscillators MCQs
4. Hartley oscillators MCQs
5. Colpitt’s oscillators MCQs
6. Phase Shift Oscillators,RC Phase Shift Oscillators MCQs
7. Wein Bridge Oscillators MCQs
8. Crystal Oscillators MCQs

Practice it now to sharpen your concept.

PRACTICE IT NOW TO SHARPEN YOUR CONCEPT AND KNOWLEDGE

• Pulse width
• Period
• Duty cycle
• Space

#### 2. When a PLL is locked on the input frequency, the VCO frequency

• Is less than f0
• Is greater than f0
• Equals f0
• Equals fin

#### 3. The bandwidth of the low-pass filter in a PLL determines the

• Capture range
• Lock range
• Free-running frequency
• Phase difference

#### 4. To generate 1kHz frequency of oscillations, the most suitable circuit is

• Hartley oscillator
• colpitts oscillator
• tuned collector oscillator
• wein Bridge oscillator

#### 5. Both positive and negative feedback is employed in

• Hartley oscillator
• colpitts oscillator
• Wien Bridge oscillator
• RC phase shift oscillator

#### 6. The application where one would most likely to find Quartz oscillator would be

• Digital clock
• Audio signal generator

#### 7. The most important characteristics of Crystal oscillator is

• It’s high efficiency
• That it requires very low DC supply
• That its output frequency is is substantially constant
• It is low cost

#### 8. To generate 1MHz signal, the most suitable circuit is

• Wein Bridge oscillator
• Colpitts oscillator
• Phase shift oscillator
• Crystal oscillator

#### 9. The loop gain of the oscillator to start with is

• Slightly more than one
• More than hundred
• Less than 1
• None of these

#### 10. An oscillator is an electronic device which converts

• Mechanical energy into electrical energy
• Electrical power into mechanical power
• DC power into AC power
• AC power into DC power and vice versa

#### 11. To obtain undamped oscillations

• Negative feedback is required
• Positive feedback is required
• Both positive and negative feedback is required
• None of these

#### 12. In RC phase shift oscillator will not produce any oscillations until and unless the voltage gain of its internal amplifier is

• More than 3 but less than 10
• Less than 20
• More than 29
• None of these

#### 13. An oscillator is a

• Rotating device
• Static electronic device
• Rotating electronic device
• Electro mechanical device

#### 14. An oscillator always needs an amplifier with

• Positive feedback
• Negative feedback
• Both types of feedback
• An LC tank circuit

#### 15. The voltage that starts an oscillator is caused by

• Ripple from the power supply
• Noise voltage in resistors
• The input signal from a generator
• Positive feedback

#### 16. The Wien-bridge oscillator is useful

• At low frequencies
• At high frequencies
• At high frequencies
• At small input signals

#### 17. A lag circuit has a phase angle that is

• Between 0 and +90 degrees
• Greater than 90 degrees
• Between 0 and -90 degrees
• The same as the input voltage

#### 18. A coupling circuit is a

• Lag circuit
• Resonant circuit

#### 19. A lead circuit has a phase angle that is

• Between 0 and +90 degrees
• Greater than 90 degrees
• Between 0 and -90 degrees
• The same as the input voltage

#### 20. A Wien-bridge oscillator uses

• Positive feedback
• Negative feedback
• Both types of feedback
• An LC tank circuit

• 0
• 1
• Low
• High

#### 22. A Wien bridge is sometimes called a

• Notch filter
• Twin-T oscillator
• Phase shifter
• Wheatstone bridge

#### 23. To vary the frequency of a Wien bridge, you can vary

• One resistor
• Two resistors
• Three resistors
• One capacitor

#### 24. The phase-shift oscillator usually has

• Two lead or lag circuits
• A twin-T filter

• 90 degrees
• 180 degrees
• 270 degrees
• 360 degrees

• Armstrong
• Clapp
• Colpitts
• Hartley

#### 27. Heavy feedback in an LC oscillator

• Prevents the circuit from starting
• Causes saturation and cutoff
• Produces maximum output voltage
• Means B is small

#### 28. When Q decreases in a Colpitts oscillator, the frequency of oscillation

• Decreases
• Remains the same
• Increases
• Becomes erratic
• Capacitive coupling
• Transformer coupling
• Resistive coupling
• Power coupling

#### 30. The Hartley oscillator uses

• Negative feedback
• Two inductors
• A tungsten lamp
• A tickler coil

#### 31. To vary the frequency of an LC oscillator, you can vary

• One resistor
• Two resistors
• Three resistors
• One capacitor

• Armstrong
• Clapp
• Colpitts
• Hartley

#### 33. The material with the piezoelectric effect is

• Quartz
• Rochelle salts
• Tourmaline
• All the above

#### 34. Crystals have a very

• Low Q
• High Q
• Small inductance
• Large resistance

#### 35. The series and parallel resonant frequencies of a crystal are

• Very close together
• Very far apart
• Equal
• Low frequencies

#### 36. The kind of oscillator found in an electronic wristwatch is the

• Armstrong
• Clapp
• Colpitts
• Quartz crystal

• 0
• 1
• 2
• 3

• 0
• 1
• 2
• 3

#### 39. The pulse width out of a one-shot multivibrator increases when the

• Supply voltage increases
• Timing resistor decreases
• UTP decreases
• Timing capacitance increases

• sinusoidal
• triangular
• rectangular
• elliptical

• Pulse width
• Period
• Duty cycle
• Space
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