Advanced Qualification · A-001 Advanced theory · A-001-004-005
What is the resonant frequency of a parallel RLC circuit if R is 4.7 kilohms, L is 15 microhenrys and C is 5 picofarads?
- A18.4 MHz
- B2.12 kHz
- C2.12 MHz
- D18.4 kHz
Correct answer: A — 18.4 MHz. From the official ISED question bank, verified word for word.
Why
The resonant frequency depends only on the inductor and capacitor values, not the resistor, so we use the standard formula with 15 microhenrys and 5 picofarads to find 18.4 MHz. 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.
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