OSCILLATORS - Quiz

1) Which is the transistor used to operate the Colpitts oscillator?

AC 127 BF 194B BC 148B AC 188

2) How many time constant period is required to fully charge a capacitor?

10 time constants 7 time constants 5 time constants 3 time constants

3) How to overcome the problem of frequency drift in LC oscillators?

Apply opposite polarity of signal Provide negative feedback Using high Q coils and good quality capacitors Increase the supply voltage

4) Why LC tuned circuits are not used in audio frequency oscillators?

LC values required is too large LC components are not available LC tank circuit does not produce AF signals LC tank circuit operation requires high voltage