I have three questions, please show all the work to help me learn the material.
ID: 1400815 • Letter: I
Question
I have three questions, please show all the work to help me learn the material.
1. An RLC circuit consists of a 60 ohm resistor, a 200 micro farad capacitor, and a 35.18 mH inductor. The current is 2.0 A rms when the circuit is connected to a 120 V/60 Hz outlet. What would be the current if this circuit were used in France where the outlets are 220 V/ 50 Hz?
2. What inductor, in mH, in series with a 57.99 ohm resistor and a 3.12 micro Farad capacitor will give a resonant frequency of 969 Hz?
3. In the circuit shown the switch is opened at t=0. At what time in milliseconds has the charge on the capacitor decreased to 10% of its initial value? A=50.7 ohms, B=45.54 ohms, C=3.1 microF and D = 10.57 ohms with V=129.2 volts.
Explanation / Answer
I = V/Z
Z = sqrt(R^2+ (XL-Xc)^2 )
XL = wL
w = 2pif
XL = 2pi*f*L = 2*pi*50*35.18 x 10^-3
XL = 11.05 ohm
Xc = 1/wC
Xc = 1/2pi*f*C = 15.92 ohm
Z = sqrt(60^2 + (15.92-11.05)^2)
Z = 60.2 ohm
I = 120/60.2 = 1.99 A
part b)
for resonating frequency
XL = Xc
f = 1/2pi*sqrt(LC)
L = 1/4pi^2*f^2*C
L = 8.65 x 10^-3 H
part c )
figure is not given
Q = Qo*e^t/T
T = time constant = RC
R = Req
0.90Q = Q*e^-t/T