Amateur Extra › E5 Electrical Principles › E5A02
E5A02
What is the resonant frequency of an RLC circuit if R is 22 ohms, L is 50 microhenries, and C is 40 picofarads?
Pick an answer to check it.
Answer: C. 3.56 MHz
f = 1 / (2 pi sqrt(LC)) = 1 / (2 x 3.1416 x sqrt(50e-6 x 40e-12)) = 1 / (2 x 3.1416 x 4.472e-8) = 3.56 MHz. Resistance does not affect the resonant frequency.
Tip: f = 1 / (2 pi sqrt(LC)); ignore R.