Chapter 8. Review Questions

1.  What is an oscillator? How is it classified?
2. Explain the main difference between an
 amplifier and an oscillator.
3. Draw a block diagram of an oscillator. State the Barkhausen criterion for oscillation.
4. Draw the circuit of Hartley oscillator and explain its working. Derive the equations for frequency of oscillation and condition for oscillation.
5.  In an Hartley oscillator
L1 = 0.2 mH
L2 = 0.3 mH
C = 0.003 micro farad
Calculate its frequency of oscillation.
6. Determine the frequency of an Hartley oscillator if L1 = 100 microH, L2 = 1mH, M = 20 microH and C = 20 picroF.
7. Draw and explain the working of Colpitts oscillator.
8. C1 = 0.16 micro F, L = 15.8 mH and frequency of oscillation is 10kHz for a Colpitts oscillator. Find out the value of the capacitor C2.
9. Explain the principle of operation of Clapp oscillator.
10. Explain briefly the working of crystal oscillator.
11. Draw the circuit diagram of a Wien-bridge oscillator and explain its working.
12. A Wien-bridge oscillator has anfrequency of 500 kHz. If the value of C is 1000pF, find the value of the resistance.