Ham Radio General Class Test FREE Ham Radio General Class Test Electronic Principles and Circuits Questions and Answers 2 — Questions and Answers
Question 1: What is the primary function of a mixer stage in a superheterodyne receiver?
- To combine two frequencies to produce sum and difference frequencies (Correct answer)
- To amplify the incoming RF signal
- To filter out unwanted harmonics
- To convert audio signals to RF
Correct answer: To combine two frequencies to produce sum and difference frequencies
A mixer combines the incoming signal with a local oscillator signal to produce intermediate frequencies, including the sum and difference of the two inputs.
Question 2: Which component is commonly used to regulate voltage in a power supply circuit?
- Transformer
- Zener diode (Correct answer)
- Inductor
- Fuse
Correct answer: Zener diode
A Zener diode is designed to maintain a constant voltage across its terminals when reverse-biased, making it ideal for voltage regulation.
Question 3: What is the approximate impedance of a half-wave dipole antenna in free space?
- 50 ohms
- 73 ohms (Correct answer)
- 100 ohms
- 300 ohms
Correct answer: 73 ohms
A half-wave dipole antenna in free space has a characteristic impedance of approximately 73 ohms.
Question 4: In a common-emitter transistor amplifier, what is the phase relationship between input and output signals?
- In phase
- 180 degrees out of phase (Correct answer)
- 90 degrees out of phase
- 45 degrees out of phase
Correct answer: 180 degrees out of phase
A common-emitter amplifier inverts the signal, producing an output that is 180 degrees out of phase with the input.
Question 5: What happens to the total capacitance when capacitors are connected in parallel?
- Total capacitance decreases
- Total capacitance is the sum of individual capacitances (Correct answer)
- Total capacitance equals the smallest value
- Total capacitance is the reciprocal of the sum of reciprocals
Correct answer: Total capacitance is the sum of individual capacitances
Capacitors in parallel add directly, so the total capacitance is the sum of all individual capacitor values.
Question 6: What is the resonant frequency of a series LC circuit with a 10 microhenry inductor and a 100 picofarad capacitor?
- 5.03 MHz (Correct answer)
- 1.59 MHz
- 15.9 MHz
- 50.3 MHz
Correct answer: 5.03 MHz
Using the formula f = 1/(2*pi*sqrt(LC)), with L = 10 uH and C = 100 pF, the resonant frequency is approximately 5.03 MHz.
Ham Radio General Class Test FREE Ham Radio General Class Test Electronic Principles and Circuits Questions and Answers 2
What is the primary function of a mixer stage in a superheterodyne receiver?