Download 1 Exam 2 Physics 2220 Fall 2015

Physics 2220
Fall 2015
Anthony Pantziris
Name:
Exam 2
Unid:
Discussion TA;
1
Show all Work!! Circle your answer(s).
Initially all capacitors are uncharged. AV = 125 V, Q = 120 uF, C2 = 70.0 uF, C3 = 30.0 uF.
(a)
(b)
(c)
(d)
[6pts.]
[8 pts.J
[3 pts.J
/'3 pts.J
The switch SA is closed leaving SB open. Calculate the charge and voltage on capacitors C] and Cj.
Now switch SA is opened and then SB is closed. Calculate the charge and voltage on each capacitor.
With switch SB still closed, close switch SA. What is the total capacitance of the circuit?
With both switches closed what is the total charge stored in the circuit?
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Physics 2220
Fall 2015
Anthony Pantziris
Name:
Unid:
Discussion TA:
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Exam 2
2
Show all Work!! Circle your answer(s).
Given the circuit shown.
(a)
(b)
(c)
(d)
f 13 pts.J Write Kirchhoffs rules as applied in this circuit.
f3 pts.J Find the currents I\, 1% and 73 as shown. If the directions are shown wrong, include a " - " sign in your
answers.
[2 pts.J Find the power used by the 7.00 £2 resistor.
[2pts.J Find the power used, or gained, by the 12.0 V battery. Explain why it is used or gained.
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Physics 2220
Discussion TA:
Fall 2015
Anthony Pantziris
3
Exam 2
J a^n Jt T.>
Show all Work!! Circle your answer(s).
Given the circuit shown. e= 50.0 V, R, = 100 ft, R2 = 250 ft, R3 = 300 ft, C = 600 uF.
(a)
(b)
(c)
(d)
(e)
[3 pts.J Find the current in R2 after the switch
is closed for a long time. fWrite llu'im equation
that snffjp,p tn snlve
f ^ pts.J Calculate the charge on the capacitor
after the switch is closed for a long time.
[4pts.] Calculate the time constant for
discharging the capacitor by opening the switch.
/ 3 pts.J What is the charge on the capacitor
2.20 s after the switch is opened?
[6 pts.J What is the current in R2 2.20 s after
the switch is opened? Show magnitude and
direction.
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