12 2-9.   What is the purpose of a buffer amplifier? 1.   To provide a direct connection between the oscillator and the load 2.   To amplify the output signal of the oscillator 3.   To remove frequency distortion from the oscillator 4.   To prevent load variations from affecting the oscillator 2-10.   Why is class A bias used in oscillators? 1.   To develop low power 2.   To develop maximum power 3.   To maintain low distortion 4.   To maintain high efficiency 2-11.   When a group of RC networks is used for regenerative feedback, which of the following waveform actions takes place in each successive stage? 1.   Waveform is rectified 2.   Amplitude is decreased 3.   Amplitude is increased 4.   Amplitude is held constant 2-12.   When RC networks are connected in cascade (series), what amount of phase shift should you see? 1.   The sum of the phase shifts of each RC network 2.   The difference between the phase shifts of each RC network 3.   The product of the phase shifts of each RC network 4.   The square of the phase shifts of each RC network 2-13.   Which of the following terms describes the gradual amplitude reduction in an oscillator? 1.   Damping 2.   Phase shift 3.   Regeneration 4.   Flywheel effect 2-14.   Which of the following formulas can be used to figure frequency in an LC tank circuit? 1. 2. 3. 4. 2-15.   Which of the following actions best describes the piezoelectric effect? 1.   Produces an dc output voltage for a given ac input voltage 2.   Produces an output voltage for a given mechanical input 3.   Produces a mechanical output for a given input voltage 4.   Both 2 and 3 above 2-16.   The piezoelectric effect is the property of a crystal which produces which of the following electrical characteristics? 1.   Resistance 2.   Inductance 3.   Capacitance 4.   Each of the above