An oscillator is a device that converts direct current (DC) from the power supply to an alternating current (AC). The signal output of an oscillator is generally of constant amplitude. An oscillator consists of a tank circuit, a transistor amplifier and a feedback circuit. The tank circuit has an inductor and capacitor connected parallel to each other. The frequency of the oscillator component is determined by the value of these components. The output of the tank circuit is amplified by the tank amplifier. The feedback circuit sends part of the output energy to the LC circuit.
Q1: Which among the following parameters acts as an initiator for the operation of an oscillator in the absence of input signal?
- Noise figure
- Noise voltage
- Noise power
- Noise temperature
Answer: (b) Noise voltage
Q2: Multivibrators belongs to which of the following category?
- Square wave oscillators
- Sinusoidal oscillators
- Ramp wave oscillators
- Triangular wave oscillators
Answer: (a) Square wave oscillators
Q3: 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
Answer: (b) UJT relaxation oscillator
Q4: In an LC oscillator, the frequency of the oscillator is……………… L or C.
- Proportional to square of
- Directly proportional to
- Independent of the values of
- Inversely proportional to the square root of
Answer: (d) Inversely proportional to the square root of
Q5: An oscillator produces……………. oscillations
- None of the above
Answer: (b) Undamped
Q6: An oscillator employs ……………… feedback
- Neither positive nor negative
- Data insufficient
Answer: (a) Positive
Q7: Which of the following is not an example for the non-sinusoidal oscillator?
- Sawtooth Generators
- Blocking oscillators
- Crystal oscillators
Answer: (d) Crystal oscillators
Q8: The sinusoidal oscillator is also called
- LC oscillator
- Harmonic oscillator
- RC oscillator
- Crystal oscillators
Answer: (b) Harmonic oscillator
Q9: Which of the following oscillators cannot be used in low-frequency oscillations?
- Wein bridge oscillators
- RC phase shift oscillators
- Colpitts oscillators
- RC oscillators
Answer: (c) Colpitts oscillators