HAM FREE HAM Radio Extra Class Test Advanced Electrical Principles Questions and Answers 2

Question 1

What is the resonant frequency of a series RLC circuit with an inductance of 10 microhenries and a capacitance of 100 picofarads?

Accepted Answer

5.03 MHz

Answer

Using f = 1/(2π√(LC)), with L = 10 µH and C = 100 pF, the resonant frequency calculates to approximately 5.03 MHz.

Question 2

In a circuit operating at 14 MHz, what is the reactance of a 300 picofarad capacitor?

Accepted Answer

37.9 ohms

Answer

Capacitive reactance Xc = 1/(2πfC) = 1/(2π × 14×10⁶ × 300×10⁻¹²) ≈ 37.9 ohms.

Question 3

What happens to the impedance of a parallel resonant circuit at the resonant frequency?

Accepted Answer

Impedance reaches its maximum value

Answer

At resonance, a parallel RLC circuit exhibits maximum impedance because the inductive and capacitive branch currents cancel each other.

Question 4

What is the skin effect in a conductor at RF frequencies?

Accepted Answer

Current tends to flow near the surface of the conductor

Answer

At RF frequencies, alternating current concentrates near the outer surface of a conductor due to electromagnetic induction, increasing effective resistance.

Question 5

What is the power factor of a circuit with a phase angle of 45 degrees between voltage and current?

Accepted Answer

0.707

Answer

Power factor equals the cosine of the phase angle, so cos(45°) = 0.707.

HAM - Radio Extra Class Test Practice Test

HAM - Radio Extra Class Test Practice Test

HAM FREE HAM Radio Extra Class Test Advanced Electrical Principles Questions and Answers 2