Phy 123L/133L
Pre-Lab: Capacitors
Name:
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Multiple choice. Choose the best answer.
(10 points possible)
1. A capacitor stores …
[1 pt]
a. charge
b. electric potential energy
c. Both a and b
d. None of the above.
2. Capacitors connected in parallel have _______ potential difference across each capacitor, but
the charge is _____ on each capacitor.
[1 pt]
a. the same, different
c. the same, the same
b. a different, the same
d. a different, different
3. Capacitors connected in series have _______ potential across each capacitor, but the charge is
_____ on each capacitor.
[1 pt]
a. the same, different
c. the same, the same
b. a different, the same
d. a different, different
4. You have two capacitors (C1 = 22 µF, C2 = 47 µF) connected in parallel. What is the
equivalent capacitance of the circuit?
[1 pt]
a. 67 µF
b. 69 µF
c. 25 µF
d.1034 µF
e. 15 µF
5. You have two capacitors (C1 = 22 µF, C2 = 47 µF) connected in series. What is the equivalent
capacitance of the circuit?
[1 pt]
a. 67 µF
b. 69 µF
c. 25 µF
d.1034 µF
e. 15 µF
6. A 5.0 µF capacitor and a resistor are connected in series in a circuit. The time constant of the
circuit is 4.0 s. Determine the value of the resistance. Pay attention to units!
[1 pt]
a. 1.25 Ω
b. 20 Ω
c. 0.8 Ω
d. 8.0x105 Ω
e. d. 8.0x10-5 Ω
Questions 7-8: A capacitor is charged up to an initial potential of V0 and connected across
a resistor. This causes a time dependent current to flow in the circuit.
7. How does the current change through time?
[1 pt]
a. It is linearly decreasing.
c. It is exponentially decreasing.
b. It is linearly increasing.
d. It is exponentially increasing.
8. If a capacitor in an RC circuit discharges slowly it means …
[1 pt]
a. the time constant is small.
c. the time constant is large.
b. the resistance is large.
d. the capacitance is small.
Questions 9-10: In parts C and D of this lab, we will measure the voltage of a RC circuit as
the capacitor discharges through a voltmeter.
9. In part D, what is Vmax equal to?
[1 pt]
a. 22 µF
b. 47 µF
c. 4 volts
d. 3.75 volts
e. ln 2
10. If we plot the natural log of the voltage vs. the time, what kind of plot do we get?
a. linearly decreasing
c. exponentially decreasing
b. linearly increasing
d. exponentially increasing
CSU Pomona
Minor Update 04/11/14
[1 pt]
Dr. Julie J. Nazareth