G7 – PRACTICAL CIRCUITS

Question 1

G7A01 (B) What useful feature does a power supply bleeder resistor provide?

Answer 1

B. It ensures that the filter capacitors are discharged when power is removed

Question 2

G7A02 (D) Which of the following components are used in a power supply filter network?

Answer 2

D. Capacitors and inductors

Question 3

G7A03 (D) What is the peak-inverse-voltage across the rectifiers in a full-wave bridge power supply?

Answer 3

D. Equal to the normal peak output voltage of the power supply

Question 4

G7A04 (D) What is the peak-inverse-voltage across the rectifier in a half-wave power supply?

Answer 4

D. Two times the normal peak output voltage of the power supply

Question 5

G7A05 (B) What portion of the AC cycle is converted to DC by a half-wave rectifier?

Answer 5

B. 180 degrees

Question 6

G7A06 (D) What portion of the AC cycle is converted to DC by a full-wave rectifier?

Answer 6

D. 360 degrees

Question 7

G7A07 (A) What is the output waveform of an unfiltered full-wave rectifier connected to a resistive load?

Answer 7

A. A series of DC pulses at twice the frequency of the AC input

Question 8

G7A08(C) Which of the following is an advantage of a switchmode power supply as compared to a linear power supply?

Answer 8

C. High frequency operation allows the use of smaller components

Question 9

G7A09 (C) Which symbol in figure G7-1 represents a field effect transistor?

Answer 9

C. Symbol 1

Question 10

G7A10 (D) Which symbol in figure G7-1 represents a Zener diode?

Answer 10

D. Symbol 5

Question 11

G7A11 (B) Which symbol in figure G7-1 represents an NPN junction transistor?

Answer 11

B. Symbol 2

Question 12

G7A12 (C) Which symbol in Figure G7-1 represents a multiple-winding transformer?

Answer 12

C. Symbol 6

Question 13

G7A13 (A) Which symbol in Figure G7-1 represents a tapped inductor?

Answer 13

A. Symbol 7

Question 14

G7B01 (A)

Complex digital circuitry can often be replaced by what type of integrated circuit?

Answer 14

A. Microcontroller

Question 15

G7B02 (A)

Which of the following is an advantage of using the binary system when processing digital signals?

Answer 15

A. Binary “ones” and “zeros” are easy to represent by an “on” or “off” state

Question 16

G7B03 (B)

Which of the following describes the function of a two input AND gate?

Answer 16

B. Output is high only when both inputs are high

Question 17

G7B04 (C)

Which of the following describes the function of a two input NOR gate?

Answer 17

C. Output is low when either or both inputs are high

Question 18

G7B05 (C)

How many states does a 3-bit binary counter have?

Answer 18

C. 8

Question 19

G7B06 (A)

What is a shift register?

Answer 19

A. A clocked array of circuits that passes data in steps along the array

Question 20

G7B07 (D)

What are the basic components of virtually all sine wave oscillators?

Answer 20

D. A filter and an amplifier operating in a feedback loop

Question 21

G7B08 (B)

How is the efficiency of an RF power amplifier determined?

Answer 21

B. Divide the RF output power by the DC input power

Question 22

G7B09 (C)

What determines the frequency of an LC oscillator?

Answer 22

C. The inductance and capacitance in the tank circuit

Question 23

G7B10 (D)

Which of the following is a characteristic of a Class A amplifier?

Answer 23

D. Low distortion

Question 24

G7B11 (B)

For which of the following modes is a Class C power stage appropriate for amplifying a modulated signal?

Answer 24

B. CW

Question 25

G7B12 (D) Which of these classes of amplifiers has the highest efficiency?

Answer 25

D. Class C

Question 26

G7B13 (B) What is the reason for neutralizing the final amplifier stage of a transmitter?

Answer 26

B. To eliminate self-oscillations

Question 27

G7B14 (B) Which of the following describes a linear amplifier?

Answer 27

B. An amplifier in which the output preserves the input waveform

Question 28

G7C01 (B) Which of the following is used to process signals from the balanced modulator then send them to the mixer in some single sideband phone transmitters?

Answer 28

B. Filter

Question 29

G7C02 (D) Which circuit is used to combine signals from the carrier oscillator and speech amplifier then send the result to the filter in some single sideband phone transmitters?

Answer 29

D. Balanced modulator

Question 30

G7C03 (C) What circuit is used to process signals from the RF amplifier and local oscillator then send the result to the IF filter in a superheterodyne receiver?

Answer 30

C. Mixer

Question 31

G7C04 (D) What circuit is used to combine signals from the IF amplifier and BFO and send the result to the AF amplifier in some single sideband receivers?

Answer 31

D. Product detector

Question 32

G7C05 (D) Which of the following is an advantage of a transceiver controlled by a direct digital synthesizer (DDS)?

Answer 32

D. Variable frequency with the stability of a crystal oscillator

Question 33

G7C06 (B) What should be the impedance of a low-pass filter as compared to the impedance of the transmission line into which it is inserted?

Answer 33

B. About the same

Question 34

G7C07 (C) What is the simplest combination of stages that implement a superheterodyne receiver?

Answer 34

C. HF oscillator, mixer, detector

Question 35

G7C08 (D) What type of circuit is used in many FM receivers to convert signals coming from the IF amplifier to audio?

Answer 35

D. Discriminator

Question 36

G7C09 (D) Which of the following is needed for a Digital Signal Processor IF filter?

Answer 36

A. An analog to digital converter B. A digital to analog converter C. A digital processor chip D. All of the these choices are correct

Question 37

G7C10 (B) How is Digital Signal Processor filtering accomplished?

Answer 37

B. By converting the signal from analog to digital and using digital processing

Question 38

G7C11 (A) What is meant by the term "software defined radio" (SDR)?

Answer 38

A. A radio in which most major signal processing functions are performed by software