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songoku
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Homework Statement
Consider the electrical circuit consisting of an E = 6 V battery, two switches S1 and S2, two resistors R1 = 4 ohm and R2 = 2 ohm, and a capacitor C = 2 [tex]\mu[/tex]F. The internal resistance of the battery may be ignored. Initially the switches are both open and the capacitor has no charge. Close the switch S1 at a certain time. At a sufficient long time after the switch S1 is closed, the capacitor is fully charged and the circuit becomes steady.
a. Just after the switch S1 is closed, what is the current flowing through the resistor R1
b. How much charge is stored in the capacitor C
c. During the period in which the capacitor is charged, how much work is done by the battery
d. During the period in which the capacitor is charged, how much thermal heat is emitted from the resistor R1
Keeping the switch S1 closed, the switch S2 is also closed. At a sufficiently long time after the switch S2 is closed, the circuit becomes steady again.
e. How much charge is stored in the capacitor C long after the switch S2 is closed
Homework Equations
Q = CV
V = IR
W = 1/2 QV
The Attempt at a Solution
a. I = V/R1 = 6/4 A
b. Q = VC = 6 x 2 = 12 [tex]\mu[/tex]C
c. W battery = 2 x W capacitor = QV = 12 x 6 = 72 [tex]\mu[/tex]J
d. W dissipated = 1/2 W battery = 36 [tex]\mu[/tex]J
e. I = V / R total = 6 / 6 = 1 A
V across Capacitor = I x R2 = 2 V
Q = CV = 2 x 2 = 4 [tex]\mu[/tex]C
Do I get it right?
thx