WorksheetsOscillator Basics
Total questions: 25
Worksheet time: 12mins
An oscillator converts ……………
a. c. power into d.c.power
d.c. power into a.c. power
mechanical power into a.c. power
none of the above
An oscillator produces……………. oscillations
Damped
Undamped
Modulated
None of the above
An oscillator employs ……………… feedback
Positive
Negative
Neither positive nor negative
Data insufficient
An oscillator differs from an amplifier because it ………
Has more gain
Requires no input signal
Requires no d.c. supply
Always has the same input
One condition for oscillation is ………….
A phase shift around the feedback loop of 180
A gain around the feedback loop of one-third
A phase shift around the feedback loop of 0
A gain around the feedback loop of less than 1
A second condition for oscillations is ……………….
A gain of 1 around the feedback loop
No gain around the feedback loop
The attention of the feedback circuit must be one-third
The feedback circuit must be capacitive
Which among the below-mentioned oscillators does not adopt any kind of feedback mechanism?
Wein bridge oscillator
UJT relaxation oscillator
Phase-shift oscillator
All of the above
Which of the following is the main advantage of using oscillators?
Suitability for low voltages
High output voltage
Constant frequency of oscillations
High frequency
In oscillator circuits the energy feedback to its input terminal from output is
Always in phase with the input signal
2700 out of phase with the input signal
1800 out of phase with the input signal
900 out of phase with the input signal
Oscillations occur with
Positive feedback having unity loop
Positive feedback having unity loop gain
Negative feedback having unity loop gain
None of the above
The gain of an ideal oscillator is
Unity
Zero
Infinity
Slightly more than unity
An oscillator can produce
Sawtooth waves
Square waves
Sine waves
Any of the above
In order to sustain oscillations in an oscillator
(a). Phase should be 00
(b). Feedback factor should be unity
(c). Both (a) and (b)
(d). Feedback should be negative
Udamped oscillation requires
Tuned circuit, amplifier and feedback circuit
Phase shift circuit amplifier and feedback circuit
Rectifier, amplifier and feedback circuit
None of the above
Another name for positive feedback
degenerative feedback
regenerative feedback
inverse feedback
Positive feedback results in _________.
decreased voltage gain
increased voltage gain
oscillation in the circuit
None of the above
In the Barkhausen criterion, the loop gain A is equal to _______.
∞
200,000
0
1
What are the two components in an oscillator
amplifier and rectifier
inverter and amplifier
amplifier and feedback
inverter and feedback
What is the definition of the period of an oscillator
the time taken for one oscillation
the time for ten swing back and forth
swing from A to B
The essential condition for sustained oscillations are________.
|Aβ|= 1, Aβ=0°
|Aβ|˂ 1, Aβ=0°
|Aβ| ˃ 1, Aβ=0°
|Aβ| ˃ 1, Aβ=0°
The function of an oscillator is to________________.
generate dc power
generate ac power at high frequency
convert unidirectional current drawn from a dc source into alternating current of frequency ranging from few Hz to GHz
convert ac power of high frequency into dc power
What is the purpose of the feedback circuit?
sinusoidal and non sinusoidal
positive feedback and amplifier
Attenuation and relaxation
Attenuation and phase shift
What is an oscillator
To produces a sinusoidal waveform on its output
To produces a non sinusoidal waveform on its output
To produces a periodic waveform on its output
To produces a periodic waveform on its input
Name the condition for an Oscillator
Ohm's law
Barkhausen Criteria
Zener Breakdown
None
An oscillator circuit is mainly ..... converter
A.C. to A.C.
D.C. to D.C.
A.C. to D.C.
D.C. to A.C
