- A. By magnetic induction
- B. By a tickler coil
- C. From the centre of split capacitors
- D. None of the above
Oscillators
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In Colpitt’s oscillator, feedback is obtained _______.
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A Wien bridge oscillator uses ______ feedback.
- A. Only positive
- B. Only negative
- C. Both positive and negative
- D. None of the above
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An oscillator produces______ oscillations.
- A. Damped
- B. Undamped
- C. Modulated
- D. None of the above
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A second condition for oscillations is_____.
- A. A gain of 1 around the feedback loop
- B. No gain around the feedback loop
- C. The attention of the feedback circuit must be one-third
- D. The feedback circuit must be capacitive
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In an LC circuit, when the capacitor is maximum, the inductor energy is ______.
- A. Minimum
- B. Maximum
- C. Half-way between maximum and minimum
- D. None of the above
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For an oscillator to properly start, the gain around the feedback loop must initially be_____.
- A. 1
- B. Greater than 1
- C. Less than 1
- D. Equal to attenuation of feedback circuit
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An oscillator differs from an amplifier because it_____.
- A. Has more gain
- B. Requires no input signal
- C. Requires no d.c. supply
- D. Always has the same input
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In an LC oscillator, the frequency of oscillator is _______ L or C.
- A. Proportional to square of
- B. Directly proportional to
- C. Independent of the values of
- D. Inversely proportional to square root of
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An LC oscillator cannot be used to produce _______ frequencies.
- A. High
- B. Audio
- C. Very low
- D. Very high
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In an LC oscillator, if the value of L is increased four times, the frequency of oscillations is_____.
- A. Increased 2 times
- B. Decreased 4 times
- C. Increased 4 times
- D. Decreased 2 times