• #### 1.  The capacitor in the circuit shown was fully charged by the battery with the switch in position a. The switch is moved to position b. In what direction does the discharging current flow?

• clockwise
• counter clockwise
• there is no current flow
• clockwise, then counter-clockwise after a period of time
• #### 2.  After the switch is closed, the current is

• 0.000045(1-e-t/RC)
• 0.000045e-t/RC

• Meters A & D
• Meters B & C
• Meters B & D
• Meters C & D
• Meters A & C
• #### 4.  The circuit above contains four identical lightbulbs connected to a battery. Which of the following procedures would increase the brightness of bulb A and decrease the brightness of bulb D?I. Replacing bulb B with an open switch II. Replacing bulb C with a closed switch III. Replacing the battery with another battery of higher voltage

• I only
• II only
• I and II only
• II and III only
• I, II, and III
• #### 5.  A student has an ohmic lightbulb connected to a battery that has significant internal resistance. As the student connects other identical lightbulbs in parallel to the first lightbulb, which of the following would be a reasonable observation about the brightnesses of the lightbulbs?

• Each lightbulb gets brighter as more lightbulbs are added.
• Each lightbulb gets dimmer as more lightbulbs are added.
• When each lightbulb is added, it is the same brightness as the first lightbulb, which remains the same brightness throughout.
• The first lightbulb remains the same brightness, but each added lightbulb is brighter than the original.
• The first lightbulb remains the same brightness, but each added lightbulb is dimmer than the original.

• A
• B
• C
• D
• E

• 0.5 ohms
• 2 ohms
• 4 ohms
• 8 ohms
• 12 ohms
• #### 8.  When the switch S is open in the circuit shown above, the reading on the ammeter A is 2.0 A. When the switch is closed, the reading on the ammeter is

• doubled
• increased slightly but not doubled
• the same
• decreased slightly but not halved
• halved
• #### 9.  Students are instructed to build the circuit shown below. The students want to open and close various switches in the circuit so that the power dissipated in bulb F is at a maximum. Which combination of open and closed switches should they use?

• Switch S3 is open, and switches S1 and S2 are closed
• Switch S1 and S3 are open, and switch S2 is closed
• Switches S2 and S3 are open, and switch S1 is closed
• Switches S1 and S2 are open, and switch S3 is closed
• Switches S1, S2, and S3 are closed
• #### 10.  A simple DC circuit consisting of a power source and a resistor is set up. The voltage of the power supply is varied, and the potential difference across the resistor and the current in the resistor is measured by a voltmeter and ammeter, respectively. The data are recorded, and a graph is constructed to determine a value for the resistor. Which of the following gives the correct relationship between voltage V and current I to create a straight line and indicates the characteristic of the graph that can be used to calculate the resistance?

• V as a function of I, and R is the inverse of the slope
• V as a function of I, and R is the slope
• I as a function of V, and R is the slope
• V as a function of I2, and R is the slope
• V as a function of I2, and R is the inverse of the slope
• #### 11.  A variable power supply is connected to identical resistors A and B in series as shown in the circuit. The potential difference The potential difference ΔV across and the rate of charge flow I through the resistor A are recorded in the table. Based on the data, which of the following statements is true?

• Resistor A is ohmic and has a resistance of 1.5 ohms
• Resistor A is ohmic and has a resistance of 7.5 ohms
• Resistor A is nonohmic and appears to increase in resistance as the potential difference across it increases
• Resistor A is nonohmic and appears to decrease in resistance as the potential difference across it increases
• It is not possible to tell if resistor A is ohmic or nonohmic from the data

• 1.5
• 6
• 9
• 54

• I only
• II only
• III only
• I and II
• II and III
• #### 14.  A circuit contains a length of tungsten wire with resistance R. An increase in the resistance would result if which of the following could be decreased?

• The resistivity of the tungsten
• The cross-sectional area of the wire
• The length of the wire
• The temperature of the wire
• The current in the wire
• #### 15.  The three lightbulbs in the circuit above are identical, and the battery has zero internal resistance. When switch S is closed to cause bulb 1 to light, which of the other two bulbs increase(s) in brightness?

• Neither bulb
• Bulb 2 only
• Bulb 3 only
• Both bulbs
• It cannot be determined without knowing the emf of the battery
• #### 16.  When the capacitor is fully charged, the voltage across the capacitor is _________ and the current in the circuit is _________.

• 45 V, 0 A
• 0 V, 45 microA
• 22.5 V, 45 micro A
• 3 microV, 0 A

• R/5
• R/4
• R/2
• R
• 2R
• #### 18.  In the circuit shown above, the battery supplies a constant voltage 𝑉 when the switch 𝑆 is closed. The value of the capacitance is 𝐶 , and the value of the resistances are 𝑅1 and 𝑅2. A long time after the switch has been closed, the current supplied by the battery is

• V/(R1 + R2)
• V/R1
• V/R2
• V(R1 + R2)/R1R2
• zero
• #### 19.  A series circuit is set up with a battery, switch, resistor, capacitor, ammeter, and voltmeter, as shown. The values of the resistor and the capacitor are unknown. Which of the following features of the circuit allow a student to determine the time constant of the circuit?

• The voltmeter is in parallel with the resistor, so its readings can be used to determine the time constant.
• The ammeter is in parallel with the capacitor, so its readings can be used to determine the time constant
• The resistor and the capacitor are in parallel, so their values can be used to determine the time constant
• The resistor and the capacitor are shown in series, so their values can be used to determine the time constant.
• The battery is in series with the resistor and capacitor, so their values can be used to determine the time constant
• #### 20.  The graph above shows the voltage as the distance along a circuit for an ideal series resistance circuit of 6 m. The current in the circuit is 0.50A. Which of the following could be the resistors in the circuit?

• 2 resistors: 4 ohms and 4 ohms
• 2 resistors: 6 ohms and 2 ohms
• 2 resistors: 3 ohms and 1 ohm
• 1 resistor: 8 ohms
• 3 resistors: 2.7 ohms, 1.3 ohms, and 4 ohms
• #### 21.  A resistor of resistance R is connected in a circuit to two identical batteries. The circuit also contains switch S and ideal voltmeter V, as shown in the figure above. The batteries both have an emf ε and internal resistance r. The reading of the voltmeter is noted with the switch in the open position. Which of the following best represents how the voltmeter reading after the switch is closed compares to the reading before the switch is closed?

• The reading of the voltmeter is the same
• The reading of the voltmeter is higher
• The reading of the voltmeter is lower
• Cannot be determined without knowing the internal resistance of the batteries
• Cannot be determined without knowing the emf of the batteries
Report Question
access_time