Ham Radio Technician Test Basic Electronics & Circuitry 3 — Questions and Answers
Question 1: What is the function of an RF choke in a ham radio circuit?
- Amplify radio frequency signals
- Block RF while passing DC (Correct answer)
- Convert AC to DC
- Tune antenna resonance
Correct answer: Block RF while passing DC
An RF choke is an inductor designed to block high-frequency RF signals while allowing DC to pass.
Question 2: What happens to inductive reactance as frequency increases?
- It decreases
- It remains constant
- It increases (Correct answer)
- It becomes zero
Correct answer: It increases
Inductive reactance (XL = 2πfL) increases proportionally with frequency.
Question 3: What is the purpose of a bypass capacitor in an amplifier circuit?
- Increase the gain at DC
- Provide a low-impedance path for AC signals around a resistor (Correct answer)
- Block all AC signals from the output
- Reduce the supply voltage
Correct answer: Provide a low-impedance path for AC signals around a resistor
A bypass capacitor provides a low-impedance AC path around a resistor, preventing signal loss.
Question 4: In a transistor, what are the three terminals called?
- Anode, cathode, gate
- Source, drain, gate
- Emitter, base, collector (Correct answer)
- Positive, negative, ground
Correct answer: Emitter, base, collector
A bipolar junction transistor (BJT) has emitter, base, and collector terminals.
Question 5: What is the resonant frequency of an LC circuit?
- The frequency at which inductive and capacitive reactances are equal (Correct answer)
- The highest frequency the circuit can pass
- The frequency where resistance equals reactance
- The frequency at which the capacitor fully charges
Correct answer: The frequency at which inductive and capacitive reactances are equal
At resonance, XL equals XC, and the circuit oscillates at its natural frequency.
Question 6: What does the prefix 'pico' represent in electronics?
- One millionth (10⁻⁶)
- One billionth (10⁻⁹)
- One trillionth (10⁻¹²) (Correct answer)
- One thousandth (10⁻³)
Correct answer: One trillionth (10⁻¹²)
Pico (p) represents 10⁻¹², so one picofarad equals 0.000000000001 farads.
Question 7: What is the primary purpose of a voltage regulator in a power supply?
- Increase the output voltage to a higher level
- Maintain a constant output voltage despite input or load changes (Correct answer)
- Convert DC voltage to AC voltage
- Filter out RF noise from the AC line
Correct answer: Maintain a constant output voltage despite input or load changes
A voltage regulator holds the output voltage steady regardless of input fluctuations or varying load current.
Ham Radio Technician Test Basic Electronics & Circuitry 3
What is the function of an RF choke in a ham radio circuit?