Free ISED Amateur Radio Advanced Qualification Examination Practice Questions

Sample Practice Questions

Try these 10 sample questions from the ISED Amateur Radio Advanced Qualification Examination practice bank. Each includes the answer and explanation. Continue with the interactive practice above to review the full question set.

1. 1In a series RC timing circuit, the capacitance stays constant while the resistance is increased. What happens to the time constant?

   1. A.It increases.Correct answer: A
   2. B.It decreases.
   3. C.It remains unchanged.
   4. D.It becomes zero.

   Explanation: OpenStax states, "Increasing the resistance increases the RC time constant". With capacitance unchanged, increasing resistance therefore lengthens the time constant.

   Reference: University Physics Volume 2, RC Circuits — RC circuit applications, intermittent windshield wiper paragraph

2. 2When arsenic is used as a donor impurity in silicon, which material type results?

   1. A.P-type semiconductor.
   2. B.N-type semiconductor.Correct answer: B
   3. C.Intrinsic semiconductor.
   4. D.Compensated semiconductor.

   Explanation: OpenStax explains that "the doped semiconductor is called an n-type semiconductor because the primary carriers of charge (electrons) are negative". A donor supplies electrons, rather than creating the hole-dominated acceptor type.

   Reference: University Physics Volume 3, Semiconductors and Doping — Semiconductors and Doping, donor impurity paragraph

3. 3A zero-offset sinusoidal voltage has an RMS value of 10 V. Approximately what is its peak-to-peak voltage?

   1. A.14.1 V.
   2. B.20.0 V.
   3. C.28.3 V.Correct answer: C
   4. D.40.0 V.

   Explanation: Analog Devices states, "The peak-to-peak amplitude of a sinusoid is the rms value multiplied by 2√2." Thus 10 V × 2√2 = 28.3 V. 14.1 V is peak rather than peak-to-peak; 20.0 V doubles RMS without the √2 factor; 40.0 V multiplies RMS by four.

   Reference: RMS Power vs. Average Power, Analog Devices — Footnote 2

4. 4How many diodes are used in a conventional single-phase full-wave bridge rectifier?

   1. A.One.
   2. B.Two.
   3. C.Four.Correct answer: C
   4. D.Six.

   Explanation: Analog Devices describes a "full-wave rectifier using 4 diodes." Two diodes can instead be used with a center-tapped secondary.

   Reference: Diode Applications: Power Supplies, Voltage Regulators and Limiters, Analog Devices — Rectification, Figure 6.2

5. 5In a phase-locked loop, which component compares the reference and oscillator signals and produces an error signal?

   1. A.Phase detector.Correct answer: A
   2. B.Loop filter.
   3. C.Voltage-controlled oscillator.
   4. D.Feedback divider.

   Explanation: Analog Devices states, "The phase detector compares the reference signal with the oscillator frequency and outputs an error signal." The loop filter and oscillator act on that signal.

   Reference: PLL glossary, Analog Devices — Definition

6. 6How many intermediate-frequency conversion stages does a dual-conversion superheterodyne receiver use?

   1. A.One.
   2. B.Two.Correct answer: B
   3. C.Three.
   4. D.Four.

   Explanation: Analog Devices describes "a dual conversion receiver with two intermediate frequency (IF) stages". Each conversion produces an IF before demodulation.

   Reference: High Speed Design Techniques, Section 3, Analog Devices — Receiver Overview, page 31

7. 7What does an antenna tuner at the transceiver output primarily adjust?

   1. A.The impedance presented to the transceiver.Correct answer: A
   2. B.The antenna's intrinsic resonant frequency.
   3. C.The feed line's characteristic impedance.
   4. D.The impedance at every point along the feed line.

   Explanation: ARRL explains that a tuner "matches the impedance of the antenna system" to the impedance the transceiver needs to see. It transforms impedance at its connection point.

   Reference: More About Antenna Tuners, ARRL — Antenna tuner function

8. 8For a series RL circuit with fixed inductance, what happens to its time constant when the resistance is doubled?

   1. A.It doubles.
   2. B.It is halved.Correct answer: B
   3. C.It remains the same.
   4. D.It becomes four times larger.

   Explanation: OpenStax states, "The time constant for an RL circuit is defined by τ=L/R". With L fixed, doubling R halves L/R. Doubling or quadrupling reverses the resistance relationship; no change ignores it.

   Reference: College Physics for AP Courses 2e, RL Circuits — Calculating Characteristic Time and Current in an RL Circuit, Strategy for (a)

9. 9Which charge carriers are the majority carriers in a p-type semiconductor?

   1. A.Electrons in the conduction band.
   2. B.Positive ions in the crystal lattice.
   3. C.Holes in the valence band.Correct answer: C
   4. D.Negative ions in the crystal lattice.

   Explanation: Analog Devices identifies "holes (the majority carriers)" in the p-type region. OpenStax describes a "mobile hole" in the valence band. The fixed dopant ions are not mobile majority carriers.

   Reference: Solid-state diodes and diode characteristics, Analog Devices — Section 5.1.3, Forward bias

10. 10What physical comparison defines the RMS voltage of an AC waveform for a resistive load?

    1. A.The DC voltage producing the same heating in that load.Correct answer: A
    2. B.The DC voltage producing the same peak electric field.
    3. C.The DC voltage equal to the waveform's highest peak.
    4. D.The DC voltage equal to the waveform's mean value.

    Explanation: Analog Devices defines the RMS value using the "amount of dc required to produce an equivalent amount of heat in the same load." Peak and mean voltage need not equal the heating-equivalent DC voltage.

    Reference: RMS Calculation for Energy Meter Applications, AN-578 — Theory of Calculation, RMS Calculation, page 2