⌕Log in
Home / License Exam / General / G7 Practical Circuits
General pool · Subelement G7

General exam G7: Practical Circuits

All 38 questions in subelement G7. The exam asks 3 of them, one from each group (G7A, G7B, G7C). Answers are hidden until you open them.

Drill these 38 questions Full practice exam

G7A

  1. G7A01 What is the function of a power supply bleeder resistor?

    1. It acts as a fuse for excess voltage
    2. It discharges the filter capacitors when power is removed
    3. It removes shock hazards from the induction coils
    4. It eliminates ground loop current
    Show answer

    B. It discharges the filter capacitors when power is removed

  2. G7A02 Which of the following components are used in a power supply filter network?

    1. Diodes
    2. Transformers and transducers
    3. Capacitors and inductors
    4. All these choices are correct
    Show answer

    C. Capacitors and inductors

  3. G7A03 Which type of rectifier circuit uses two diodes and a center-tapped transformer?

    1. Full-wave
    2. Full-wave bridge
    3. Half-wave
    4. Synchronous
    Show answer

    A. Full-wave

  4. G7A04 What is characteristic of a half-wave rectifier in a power supply?

    1. Only one diode is required
    2. The ripple frequency is twice that of a full-wave rectifier
    3. More current can be drawn from the half-wave rectifier
    4. The output voltage is two times the peak input voltage
    Show answer

    A. Only one diode is required

  5. G7A05 What portion of the AC cycle is converted to DC by a half-wave rectifier?

    1. 90 degrees
    2. 180 degrees
    3. 270 degrees
    4. 360 degrees
    Show answer

    B. 180 degrees

  6. G7A06 What portion of the AC cycle is converted to DC by a full-wave rectifier?

    1. 90 degrees
    2. 180 degrees
    3. 270 degrees
    4. 360 degrees
    Show answer

    D. 360 degrees

  7. G7A07 What is the output waveform of an unfiltered full-wave rectifier connected to a resistive load?

    1. A series of DC pulses at twice the frequency of the AC input
    2. A series of DC pulses at the same frequency as the AC input
    3. A sine wave at half the frequency of the AC input
    4. A steady DC voltage
    Show answer

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

  8. G7A08 Which of the following is characteristic of a switchmode power supply as compared to a linear power supply?

    1. Faster switching time makes higher output voltage possible
    2. Fewer circuit components are required
    3. High-frequency operation allows the use of smaller components
    4. Inherently more stable
    Show answer

    C. High-frequency operation allows the use of smaller components

  9. G7A09 Which symbol in figure G7-1 represents a field effect transistor?

    Figure G7-1 from the question pool
    1. Symbol 2
    2. Symbol 5
    3. Symbol 1
    4. Symbol 4
    Show answer

    C. Symbol 1

  10. G7A10 Which symbol in figure G7-1 represents a Zener diode?

    Figure G7-1 from the question pool
    1. Symbol 4
    2. Symbol 1
    3. Symbol 11
    4. Symbol 5
    Show answer

    D. Symbol 5

  11. G7A11 Which symbol in figure G7-1 represents an NPN junction transistor?

    Figure G7-1 from the question pool
    1. Symbol 1
    2. Symbol 2
    3. Symbol 7
    4. Symbol 11
    Show answer

    B. Symbol 2

  12. G7A12 Which symbol in Figure G7-1 represents a solid core transformer?

    Figure G7-1 from the question pool
    1. Symbol 4
    2. Symbol 7
    3. Symbol 6
    4. Symbol 1
    Show answer

    C. Symbol 6

  13. G7A13 Which symbol in Figure G7-1 represents a tapped inductor?

    Figure G7-1 from the question pool
    1. Symbol 7
    2. Symbol 11
    3. Symbol 6
    4. Symbol 1
    Show answer

    A. Symbol 7

G7B

  1. G7B01 What is the purpose of neutralizing an amplifier?

    1. To limit the modulation index
    2. To eliminate self-oscillations
    3. To cut off the final amplifier during standby periods
    4. To keep the carrier on frequency
    Show answer

    B. To eliminate self-oscillations

  2. G7B02 Which of these classes of amplifiers has the highest efficiency?

    1. Class A
    2. Class B
    3. Class AB
    4. Class C
    Show answer

    D. Class C

  3. G7B03 Which of the following describes the function of a two-input AND gate?

    1. Output is high when either or both inputs are low
    2. Output is high only when both inputs are high
    3. Output is low when either or both inputs are high
    4. Output is low only when both inputs are high
    Show answer

    B. Output is high only when both inputs are high

  4. G7B04 In a Class A amplifier, what percentage of the time does the amplifying device conduct?

    1. 100%
    2. More than 50% but less than 100%
    3. 50%
    4. Less than 50%
    Show answer

    A. 100%

  5. G7B05 How many states does a 3-bit binary counter have?

    1. 3
    2. 6
    3. 8
    4. 16
    Show answer

    C. 8

  6. G7B06 What is a shift register?

    1. A clocked array of circuits that passes data in steps along the array
    2. An array of operational amplifiers used for tri-state arithmetic operations
    3. A digital mixer
    4. An analog mixer
    Show answer

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

  7. G7B07 Which of the following are basic components of a sine wave oscillator?

    1. An amplifier and a divider
    2. A frequency multiplier and a mixer
    3. A circulator and a filter operating in a feed-forward loop
    4. A filter and an amplifier operating in a feedback loop
    Show answer

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

  8. G7B08 How is the efficiency of an RF power amplifier determined?

    1. Divide the DC input power by the DC output power
    2. Divide the RF output power by the DC input power
    3. Multiply the RF input power by the reciprocal of the RF output power
    4. Add the RF input power to the DC output power
    Show answer

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

  9. G7B09 What determines the frequency of an LC oscillator?

    1. The number of stages in the counter
    2. The number of stages in the divider
    3. The inductance and capacitance in the tank circuit
    4. The time delay of the lag circuit
    Show answer

    C. The inductance and capacitance in the tank circuit

  10. G7B10 Which of the following describes a linear amplifier?

    1. Any RF power amplifier used in conjunction with an amateur transceiver
    2. An amplifier in which the output preserves the input waveform
    3. A Class C high efficiency amplifier
    4. An amplifier used as a frequency multiplier
    Show answer

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

  11. G7B11 For which of the following modes is a Class C power stage appropriate for amplifying a modulated signal?

    1. SSB
    2. FM
    3. AM
    4. All these choices are correct
    Show answer

    B. FM

G7C

  1. G7C01 What circuit is used to select one of the sidebands from a balanced modulator?

    1. Carrier oscillator
    2. Filter
    3. IF amplifier
    4. RF amplifier
    Show answer

    B. Filter

  2. G7C02 What output is produced by a balanced modulator?

    1. Frequency modulated RF
    2. Audio with equalized frequency response
    3. Audio extracted from the modulation signal
    4. Double-sideband modulated RF
    Show answer

    D. Double-sideband modulated RF

  3. G7C03 What is one reason to use an impedance matching transformer at a transmitter output?

    1. To minimize transmitter power output
    2. To present the desired impedance to the transmitter and feed line
    3. To reduce power supply ripple
    4. To minimize radiation resistance
    Show answer

    B. To present the desired impedance to the transmitter and feed line

  4. G7C04 How is a product detector used?

    1. Used in test gear to detect spurious mixing products
    2. Used in a transmitter to perform frequency multiplication
    3. Used in an FM receiver to filter out unwanted sidebands
    4. Used in a single sideband receiver to extract the modulated signal
    Show answer

    D. Used in a single sideband receiver to extract the modulated signal

  5. G7C05 Which of the following is characteristic of a direct digital synthesizer (DDS)?

    1. Extremely narrow tuning range
    2. Relatively high-power output
    3. Pure sine wave output
    4. Variable output frequency with the stability of a crystal oscillator
    Show answer

    D. Variable output frequency with the stability of a crystal oscillator

  6. G7C06 Which of the following is an advantage of a digital signal processing (DSP) filter compared to an analog filter?

    1. A wide range of filter bandwidths and shapes can be created
    2. Fewer digital components are required
    3. Mixing products are greatly reduced
    4. The DSP filter is much more effective at VHF frequencies
    Show answer

    A. A wide range of filter bandwidths and shapes can be created

  7. G7C07 What term specifies a filter’s attenuation inside its passband?

    1. Insertion loss
    2. Return loss
    3. Q
    4. Ultimate rejection
    Show answer

    A. Insertion loss

  8. G7C08 Which parameter affects receiver sensitivity?

    1. Input amplifier gain
    2. Demodulator stage bandwidth
    3. Input amplifier noise figure
    4. All these choices are correct
    Show answer

    D. All these choices are correct

  9. G7C09 What is the phase difference between the I and Q RF signals that software-defined radio (SDR) equipment uses for modulation and demodulation?

    1. Zero
    2. 90 degrees
    3. 180 degrees
    4. 45 degrees
    Show answer

    B. 90 degrees

  10. G7C10 What is an advantage of using I-Q modulation with software-defined radios (SDRs)?

    1. The need for high resolution analog-to-digital converters is eliminated
    2. All types of modulation can be created with appropriate processing
    3. Minimum detectible signal level is reduced
    4. Automatic conversion of the signal from digital to analog
    Show answer

    B. All types of modulation can be created with appropriate processing

  11. G7C11 Which of these functions is performed by software in a software-defined radio (SDR)?

    1. Filtering
    2. Detection
    3. Modulation
    4. All these choices are correct
    Show answer

    D. All these choices are correct

  12. G7C12 What is the frequency above which a low-pass filter’s output power is less than half the input power?

    1. Notch frequency
    2. Neper frequency
    3. Cutoff frequency
    4. Rolloff frequency
    Show answer

    C. Cutoff frequency

  13. G7C13 What term specifies a filter’s maximum ability to reject signals outside its passband?

    1. Notch depth
    2. Rolloff
    3. Insertion loss
    4. Ultimate rejection
    Show answer

    D. Ultimate rejection

  14. G7C14 The bandwidth of a band-pass filter is measured between what two frequencies?

    1. Upper and lower half-power
    2. Cutoff and rolloff
    3. Pole and zero
    4. Image and harmonic
    Show answer

    A. Upper and lower half-power

Questions: NCVEC Question Pool Committee (public domain). Pool valid July 1, 2023 – June 30, 2027.