Q.1
Which of the following is (are) the determining factor(s) of the stability of a feedback amplifier?
  • A
  • Phase shift between input and output signals
  • Both A and the phase shift between input and output signals
  • None of the above
Q.2
What is the minimum frequency at which a crystal will oscillate?
  • seventh harmonic
  • third harmonic
  • fundamental
  • second harmonic
Q.3
The attenuation of the three-section RC feedback phase-shift oscillator is
  • 1/9.
  • 1/30.
  • 1/3.
  • 1/29.
Q.4
The feedback signal in a(n) ________ oscillator is derived from an inductive voltage divider in the LC circuit.
  • Hartley
  • Armstrong
  • Colpitts
  • None of these
Q.5
Which of the following improvements is (are) a result of the negative feedback in a circuit?
  • Lower output impedance
  • Reduced noise
  • More linear operation
  • All of the above
Q.6
The piezoelectric effect in a crystal is ___________
  • A voltage developed because of mechanical stress
  • A change in resistance because of temperature
  • A change in frequency because of temperature
  • None of the above
Q.7
In an LC oscillator, if the value of L is increased four times, the frequency of oscillations is ___________
  • Increased 2 times
  • Decreased 4 times
  • Increased 4 times
  • Decreased 2 times
Q.8
In a Wien-bridge oscillator, if the resistances in the positive feedback circuit are decreased, the frequency ___________
  • Remains the same
  • Decreases
  • Increases
  • Insufficient data
Q.9
If the crystal frequency changes with temperature, we say that crystal has ___________ temperature coefficient
  • Negative
  • Positive
  • Zero
  • None of the above
Q.10
The Q of the crystal is of the order of ___________
  • 100
  • 1000
  • 50
  • More than 10,000
Q.11
In Colpitt's oscillator, feedback is obtained ___________
  • By magnetic induction
  • By a tickler coil
  • From the centre of split capacitors
  • None of the above
Q.12
An important limitation of a crystal oscillator is ___________
  • Its low output
  • Its high Q
  • Less availability of quartz crystal
  • Its high output
Q.13
___________ is a fixed frequency oscillator
  • Phase-shift oscillator
  • Hartely-oscillator
  • Colpitt's oscillator
  • Crystal oscillator
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