A series RLC circuit is driven by a 1.0-kHz oscillator.The circuit parameters are L = 5.0 mH,C = 4.0 $\mu$F,R = 10 $\Omega$.If you adjust the frequency of the oscillator so that it is at the resonance frequency of the RLC circuit,and if it supplies 3.0 V rms,what is the rms current in the circuit?
A)0.23 A
B)0.36 A
C)0.21 A
D)0.30 A
E)0.42 A

Question

Quizplus · Accepted Answer

The resonant frequency of the circuit is given by:

f = 1 / (2π √(LC))

= 1 / (2π √(5.0 mH × 4.0 μF))

= 1 / (2π × 2.0 × 10^-3)

= 79.6 Hz

Since the oscillator is supplying 1 kHz, which is much greater than the resonant frequency, the circuit is in resonance.

The impedance of the circuit at resonance is:

Z = R

= 10 Ω

Therefore, the current in the circuit is:

I = V / Z

= (3.0 V rms) / (10 Ω)

= 0.30 A rms

Thus, the answer is D.

A Series RLC Circuit Is Driven by a 1 μ\muμ F,R = 10

A Series RLC Circuit Is Driven by a 1 $\mu$ F,R = 10