Question

For a series RLC circuit, excited by voltage V = 20 sinωt. The values of R = 2 Ω, L = 1mH and C = 0.4 µF. The resonant frequency of the circuit is ______________

(a) 20 krad/s

(b) 30 krad/s

(c) 40 krad/s

(d) 50 krad/s

Answer 1

Right answer is (d) 50 krad/s

To explain: We know that the resonant frequency w0 = 1/(LC)^0.5

Given R = 2 Ω, L = 1mH and C = 0.4 µF.

So, w0 = (frac{1}{sqrt{10^{-3}×0.4×10^{-6}}})

Or, w0 = 50 krad/s.