1 For the circuit shown what countdown is necessary from the

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1. For the circuit shown, what countdown is necessary from the divider circuit to produce an output frequency of 10 MHz? (Assume a reference frequency of 100 kHz.)

A. 10

B. 10,000

C. 100

D. 1,000

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2. Look at the circuit diagram shown. An electronics technician measures a voltage of 25.7 V at the collector ofQ₂. Which of the following statements about this circuit is correct?

A. The circuit is operating normally.

B. Resistor R₁ is open in the circuit.

C. Resistor R₃ has increased in value.

D. An emitter-to-base short is present in Q₁.

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3. In the circuit illustrated in the figure, which of the following are frequency-determining components?

A. R₁ and R₂

B. R₂ and R₅

C. C₁ and R₃

D. R₁ and C₄

4. To recover audio from a received single sideband signal, the receiver must

A. have several stages of frequency multiplication.

B. reinsert the missing carrier.

C. have an extremely narrow bandwidth.

D. contain a balanced modulator.

5. Which of the following statements about series regulators is correct?

A. Series regulators are inherently more efficient than shunt regulators because the current through the shunt regulator flows through the load.

B. Series regulators are inherently less efficient than shunt regulators because the current through the shunt regulator doesn\'t flow through the load.

C. Series regulators are inherently more efficient than shunt regulators because the current through the shunt regulator doesn\'t flow through the load.

D. Series regulators are inherently less efficient than shunt regulators because the current through the shunt regulator flows through the load.

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6. In the circuit illustrated, which of the following factors determines the accuracy of the output frequency?

A. The accuracy of the reference signal

B. The stability of the phase detector

C. The stability of the VCO

D. The accuracy of the divider

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7. Look at the schematic diagram shown. This circuit diagram represents a/an

A. full-wave rectifier.

B. frequency synthesizer.

C. Wein bridge oscillator.

D. audio amplifier.

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8. In the circuit shown, an electronics technician measures the output voltage of the regulator circuit at 30 V. Which of the following statements about this circuit is correct?

A. Resistor R₂ is shorted.

B. The collector-to-emitter junction is open in Q₁.

C. Resistor R₁ is open.

D. Resistor R₄ is open.

9. Which of the following represents an invalid DTMF tone pair?

A. 941 and 1209

B. 1336 and 852

C. 1336 and 770

D. 1633 and 1477

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10. Look at the schematic diagram shown in the figure. In this circuit, the lamp will light only when

A. S₂ is closed and S₁ is in position A, position B, or position C.

B. S₂ is closed and S₁ is in position A or position B.

C. S₂ is closed and S₁ is in position A.

D. S₂ is closed and S₁ is in position B.

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11. Look at the schematic diagram and the four waveforms that are shown. Which of the following statements about this circuit is correct?

A. No combination of closed switches will produce waveform 3 at the output of this circuit.

B. To obtain waveform 3 at the output of this circuit, both switch S₁ and switch S₃ would have to be closed.

C. To obtain waveform 3 at the output of this circuit, only switch S₂ must be closed.

D. To obtain waveform 3 at the output of this circuit, either switch S₁ or switch S₃ must be closed.

12. For a circuit to oscillate, it\'s absolutely essential that the circuit have

A. degenerative feedback.

B. a gain of less than unity.

C. regenerative feedback.

D. negative resistance.

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13. Look at the schematic diagram shown in the figure. This schematic diagram represents a _______ oscillator.

A. relaxation

B. twin-T

C. phase-shift

D. Wein bridge

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14. When a load is applied to the power supply in the circuit shown, the output voltage tends to decrease. Which of the following actions in the circuit counteracts this tendency?

A. The voltage at the junction of R₃ and R₄ increases.

B. The conduction of Q₂ decreases.

C. The voltage at the emitter of Q₂ increases.

D. The conduction of Q₁ decreases.

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15. Look at the circuit diagram and the four waveforms that are shown. Which of the following waveforms will be produced when only S₁ is closed?

A. Waveform 4

B. Waveform 2

C. Waveform 3

D. Waveform 1

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16. Look at the block diagram shown. Which of the following multiplication factors must take place in the two unmarked stages to obtain the 60 kHz output?

A. × 6 and × 6

B. × 6 and × 2

C. × 5 and × 5

D. × 3 and × 2

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17. Look at the circuit diagram and the four waveforms that are shown. Which of the four ripple waveforms shown would result if D₂ were to open?

A. Waveform 2

B. Waveform 1

C. Waveform 4

D. Waveform 3

18. A modulation technique that uses two tones that are separated in frequency is called

A. FSK.

B. DTMF.

C. CTSS.

D. SSB.

19. Which of the following does a relaxation oscillator depend on for proper operation?

A. Negative resistance

B. Positive feedback

C. Negative feedback

D. Frequency synthesis

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20. At which of the following points in the circuit shown would it be normal to measure a varying DC voltage?

A. Point 3

B. Point 4

C. Point 1

D. Point 2

1. 100