Oscillators MCQ Questions and Answers for the EE AND ECE engineering students.
Q 1 . An oscillator converts ………………
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c. power into d.c. power
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c. power into a.c. power
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mechanical power into a.c. power
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none of the above
Answer : 2
Q 2 . In an LC transistor oscillator, the active device is ……………
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LC tank circuit
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Biasing circuit
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Transistor
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None of the above
Answer : 3
Q 3 . In an LC circuit, when the capacitor is maximum, the inductor energy is ……….
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Minimum
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Maximum
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Half-way between maximum and minimum
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None of the above
Answer : 1
Q 4 . In an LC oscillator, the frequency of oscillator is ……………. L or C.
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Proportional to square of
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Directly proportional to
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Independent of the values of
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Inversely proportional to square root of
Answer : 4
Q 5 . An oscillator produces……………. oscillations
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Damped
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Undamped
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Modulated
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None of the above
Answer : 2
Q 6 . An oscillator employs ……………… feedback
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Positive
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Negative
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Neither positive nor negative
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Data insufficient
Answer : 1
Q 7 . An LC oscillator cannot be used to produce ………………… frequencies
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High
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Audio
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Very low
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Very high
Answer : 3
Q 8 . Hartley oscillator is commonly used in ………………
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Radio receivers
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Radio transmitters
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TV receivers
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None of the above
Answer : 1
Q 9 . In a phase shift oscillator, we use …………. RC sections
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Two
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Three
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Four
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None of the above
Answer : 2
Q 1 0 . In a phase shift oscillator, the frequency determining elements are …………
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L and C
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R, L and C
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R and C
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None of the above
Answer : 3
Q 1 1 . A Wien bridge oscillator uses ……………. feedback
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Only positive
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Only negative
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Both positive and negative
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None of the above
Answer : 3
Q 1 2 . The piezoelectric effect in a crystal is ……………
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A voltage developed because of mechanical stress
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A change in resistance because of temperature
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A change in frequency because of temperature
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None of the above
Answer : 1
Q 1 3 . If the crystal frequency changes with temperature, we say that crystal has …………… temperature coefficient
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Positive
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Zero
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Negative
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None of the above
Answer : 1
Q 1 4 . The crystal oscillator frequency is very stable due to ………………. of the crystal
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Rigidity
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Vibrations
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Low Q
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High Q
Answer : 4
Q 1 5 . The application where one would most likely find a crystal oscillator is ………………
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Radio receiver
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Radio transmitter
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AF sweep generator
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None of the above
Answer : 2
Q 1 6 . An oscillator differs from an amplifier because it ………
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Has more gain
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Requires no input signal
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Requires no d.c. supply
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Always has the same input
Answer : 2
Q 1 7 . One condition for oscillation is ………….
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A phase shift around the feedback loop of 180o
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A gain around the feedback loop of one-third
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A phase shift around the feedback loop of 0o
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A gain around the feedback loop of less than 1
Answer : 3
Q 1 8 . A second condition for oscillations is ……………….
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A gain of 1 around the feedback loop
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No gain around the feedback loop
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The attention of the feedback circuit must be one-third
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The feedback circuit must be capacitive
Answer : 1
Q 1 9 . In a certain oscillator A v = 50. The attention of the feedback circuit must be …………
1. | 1 |
---|---|
2. | 01 |
3. | 10 |
4. | 02 |
Answer : 4
Q 2 0 . For an oscillator to properly start, the gain around the feedback loop must initially be
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1
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Greater than 1
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Less than 1
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Equal to attenuation of feedback circuit
Answer : 2
Q 2 1 . In a Wien-bridge oscillator, if the resistances in the positive feedback circuit are decreased, the frequency……….
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Remains the same
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Decreases
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Increases
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Insufficient data
Answer : 3
Q 2 2 . In Colpitt’s oscillator, feedback is obtained …………….
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By magnetic induction
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By a tickler coil
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From the centre of split capacitors
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None of the above
Answer : 3
Q 2 3 . The Q of the crystal is of the order of …………
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100
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1000
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50
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More than 10,000
Answer : 4
Q 2 4 . Quartz crystal is most commonly used in crystal oscillators because ………….
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It has superior electrical properties
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It is easily available
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It is quite inexpensive
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None of the above
Answer : 1
Q 2 5 . This question will be available soon
Q 2 6 . This question will be available soon
Q 2 7 . …………… is a fixed frequency oscillator
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Phase-shift oscillator
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Hartely-oscillator
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Colpitt’s oscillator
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Crystal oscillator
Answer : 4
Q 2 8 . In an LC oscillator, if the value of L is increased four times, the frequency of oscillations is …………
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Increased 2 times
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Decreased 4 times
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Increased 4 times
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Decreased 2 times
Answer : 4
Q 2 9 . An important limitation of a crystal oscillator is ……………
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Its low output
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Its high Q
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Less availability of quartz crystal
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Its high output
Answer : 1
Q 3 0 . The signal generator generally used in the laboratories is …………… oscillator
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Wien-bridge
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Hartely
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Crystal
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Phase shift
Answer : 1