Electronic Devices and Circuit Theory-Oscillator Circuits
Electronic Devices and Circuit Theory-Oscillator Circuits
1. 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
2. The feedback signal in a(n) ________ oscillator is derived from an inductive voltage divider in the LC circuit.
- Hartley
- Armstrong
- Colpitts
- [NIL]
3. The attenuation of the three-section RC feedback phase-shift oscillator is
- 1/9.
- 1/30.
- 1/3.
- 1/29.
4. For a phase-shift oscillator, the gain of the amplifier stage must be greater than ________.
- 19
- 29
- 30
- 1
5. 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
6. What is the minimum frequency at which a crystal will oscillate?
- seventh harmonic
- third harmonic
- fundamental
- second harmonic
7. An amplifier with a gain of –500 and a feedback of = –0.1 has a gain change of 15% due to temperature. Calculate the change in gain of the feedback amplifier.
- 0.2%
- 0.3%
- 0.4%
- 0.5%
8. The feedback signal in a(n) ________ oscillator is derived from a capacitive voltage divider in the LC circuit.
- Hartley
- Armstrong
- Colpitts
10. A circuit that can change the frequency of oscillation with an application of a dc voltage is sometimes called
- a voltage-controlled oscillator.
- a crystal oscillator.
- a Hartley oscillator.
- an astable multivibrator.