Advanced Qualification · A-001 Advanced theory · A-001-003-001
What is the resonant frequency of a series RLC circuit if R is 47 ohms, L is 50 microhenrys and C is 40 picofarads?
- A7.96 MHz
- B79.6 MHz
- C3.56 MHz
- D1.78 MHz
Correct answer: C — 3.56 MHz. From the official ISED question bank, verified word for word.
Why
The resonant frequency of 3.56 MHz is correct because it is the specific point where the inductive and capacitive reactances cancel each other out in a series circuit, leaving only the resistance to limit the current. The full explanation — and one for every question — is in Pro.
Practise this section
Advanced theory is section A-001 of the Advanced exam: Advanced theory: time constants, reactance, impedance, resonance, Q, and the mathematics behind tuned circuits.
Drill A-001 — free, no account