Consider an LC circuit in which L = 490 mH and C = 0.116 �F.

(a) What is the resonance frequency ?0?
krad/s

(b) If a resistance of 1.02 k? is introduced into this circuit, what is the frequency of the damped oscillations?


(c) By what percentage does the frequency of the damped oscillations differ from the resonance frequency?

Respuesta :

Answer:

(a) 4190 rad/sec

(b) 4064 rad/sec

(c) Percentage change is 3 %  

Explanation:

We have given inductance [tex]L=490mH=490\times 10^{-3}H[/tex]

Capacitance [tex]C=0.116\mu F=0.116\times 10^{-6}F[/tex]

We know that resonance frequency is given by [tex]\omega =\frac{1}{\sqrt{LC}}=\frac{1}{\sqrt{490\times 10^{-3}\times 0.116\times 10^{-6}}}=4190rad/sec[/tex]

Now resistance is given as R = 1020 ohm '

(b) We know that damped frequency is given by

[tex]\omega =\sqrt{\frac{1}{LC}-(\frac{R}{2L})^2}=\sqrt{\frac{1}{490\times 10^{-3}\times 0.116\times 10^{-3}}-(\frac{1020}{2\times 490\times 10^{-3}})^2}=4064rad/sec[/tex]

(c) Percentage change in frequency [tex]=\frac{4190-4064}{4190}\times 100=3[/tex]%