1 Look at the schematic diagram shown in the figure above Wh

1. Look at the schematic diagram shown in the figure above. What type of oscillator is represented in the circuit? A. Hartley B. Relaxation C. Armstrong D. Phase-shift

2. Which of the following devices would you use to stabilize frequency in communications equipment? A. A quartz crystal B. An inductor C. A transformer D. A capacitor

3. Which of the following oscillators depends on a coil capacitor ratio to determine the amount of feedback in the circuit? A. A phase-shift oscillator B. A twin-T oscillator C. A Colpitts oscillator D. A multivibrator oscillator

4. An oscillator with a feedback loop that uses only resistors and capacitors to determine frequency is called a _______ oscillator. A. twin-T B. Colpitts C. multivibrator D. phase-shift

5. Which of the following types of oscillators uses an untapped coil and a pair of capacitors as a signal voltage divider? A. A Hartley oscillator B. An Armstrong oscillator C. A multivibrator oscillator D. A Colpitts oscillator

6. Look at the circuit schematic shown in the figure above. Which of the following circuits is represented by this schematic? A. A phase-shift oscillator circuit B. A Colpitts oscillator circuit C. A relaxation oscillator circuit D. A Pierce oscillator circuit

7. The main disadvantage of using negative feedback in an amplifier circuit is a loss in A. gain. B. frequency. C. sinusoidal waveforms. D. phase shift.

8. Which of the following multivibrators is often called a flip-flop? A. A bistable multivibrator B. A monostable multivibrator C. A free-running multivibrator D. An astable multivibrator

9. Which of the following types of oscillators generates a signal that has a sawtooth waveform? A. Phase-shift B. Colpitts C. Relaxation D. Pierce

10. Which of the following types of oscillators is used to generate RF signals below 1,000 MHz, and also to generate AF signals? A. Multivibrator oscillator B. Armstrong oscillator C. Colpitts oscillator D. Hartley oscillator

11. The percent of frequency error is determined by dividing the error by the operating frequency and multiplying by 100. What would be the percent of frequency error of an oscillator that operates at 40 MHz when the oscillator is off by 2,000 Hz? A. 0.005% B. 0.02% C. 0.0005% D. 0.002%

12. Which of the following circuits is widely used to interface high-speed digital data circuits, and also to protect computers from the high-voltage circuits they control? A. The Colpitts oscillator B. The phase-shift oscillator C. The twin-T oscillator D. The optical isolator circuit

13. Look at the block diagram shown in the figure above. According to the information provided by the diagram, the frequency of the offset oscillator is _______ MHz. A. 6.1 B. 10.7 C. 2.5 D. 0

14. A diathermy machine is considered a member of the _______-heater family. A. dielectric B. conduction C. induction D. infrared

15. In an amplifier with a very high gain, undesired oscillations are called _______ oscillations. A. parasitic B. impaired C. unwarranted D. square-wave

16. A phase-shift oscillator operates at its designed frequency when the total phase shift in the feedback circuit is ______ degrees. A. 90 B. 180 C. 135 D. 80

17. The function of the circuit shown in the figure above is to provide electrical ________ between input and output signals. A. power B. gain C. isolation D. interference

18. To determine the frequency at which feedback occurs in a sound system, you can use an instrument called a A. function generator. B. transformer. C. graphic equalizer. D. Hartley oscillator.

19. Determine the percent of frequency error of an oscillator that operates at 30 MHz when the oscillator is off by 1,500 Hz. A. 0.0005% B. 0.002% C. 0.005% D. 0.02%

20. Look at the circuit diagram shown in the figure above. The type of circuit shown is a/an ______ circuit. A. Armstrong oscillator B. twin-T oscillator C. optical isolator D. phase-shift oscillator

Solution

1. the figure shows the Armstrong circuit.

therefore the correct option is (C).

2.A quartz crystal is used to stabilize frequency in communications equipment

therefore the correct option is (A).

3.A Colpitts oscillator depends on a coil capacitor ratio to determine the amount of feedback in the circuit.

therefore the correct option is (C).

5.A Colpitts oscillator uses an untapped coil and a pair of capacitors as a signal voltage divider.

therefore the correct option is (D).

6. Colpitts oscillator circuit

therefore the correct option is (B).

7.The main disadvantage of using negative feedback in an amplifier circuit is a loss in gain

therefore the correct option is (A).

8.A bistable multivibrator is called as a  flip-flop.

therefore the correct option is (A).

16. A phase-shift oscillator operates at its designed frequency when the total phase shift in the feedback circuit is 180 degrees.

therefore the correct option is (B).

17. The function of the circuit shown in the figure above is to provide electrical isolation between input and output signals.

therefore the correct option is (C).

20. the figure shows the optical isolator circuit.

therefore the correct option is (C).