Chapter 25: Electric Current and Direct
Current Circuits
If 4.7  1016 electrons pass a particular point
in a wire every second, what is the current in
the wire?
A. 4.7 mA
B. 7.5 A
C. 2.9 A
D. 7.5 mA
E. 0.29 A
If 4.7  1016 electrons pass a particular point
in a wire every second, what is the current in
the wire?
A. 4.7 mA
B. 7.5 A
C. 2.9 A
D. 7.5 mA
E. 0.29 A
The graph shows the potential difference
across a resistor as a function of the current
through the resistor. The slope of the resulting
curve represents
A. power.
B. resistance.
C. emf.
D. charge.
E. work per unit charge.
The graph shows the potential difference
across a resistor as a function of the current
through the resistor. The slope of the resulting
curve represents
A. power.
B. resistance.
C. emf.
D. charge.
E. work per unit charge.
A resistor carries a current I. The power
dissipated in the resistor is P. What is the
power dissipated if the same resistor carries
current 3I?
A. P
B. 3P
C. P/3
D. 9P
E. P/9
A resistor carries a current I. The power
dissipated in the resistor is P. What is the
power dissipated if the same resistor carries
current 3I?
A. P
B. 3P
C. P/3
D. 9P
E. P/9
The power dissipated in each of two
resistors is the same. The potential drop
across resistor A is twice that across resistor
B. If the resistance of resistor B is R, what
is the resistance of A?
A. R
B. 2R
C. R/2
D. 4R
E. R/4
The power dissipated in each of two
resistors is the same. The potential drop
across resistor A is twice that across resistor
B. If the resistance of resistor B is R, what
is the resistance of A?
A. R
B. 2R
C. R/2
D. 4R
E. R/4
Two resistors are connected in series across a
potential difference. If the current carried by
resistor A is I, what is the current carried by B?
A.
I
B.
2I
C. I/2
D. 4I
E. impossible to determine unless more is
known about the resistances of A and B
Two resistors are connected in series across a
potential difference. If the current carried by
resistor A is I, what is the current carried by B?
A. I
B.
2I
C. I/2
D. 4I
E. impossible to determine unless more is
known about the resistances of A and B
Four identical light bulbs are
connected to a power
supply as shown. Which
light bulb consumes the
most power?
B1
A. B1
B4
B. B2
C. B3
D. B4
B2
B3


V
E. They all consume the same amount of
power.
Four identical light bulbs are
connected to a power
supply as shown. Which
light bulb consumes the
most power?
B1
A. B1
B4
B. B2
C. B3
D. B4
B2
B3


V
E. They all consume the same amount of
power.
Four identical light bulbs are
connected to a power supply as
B1
shown. Which light bulb
consumes the most power?
B2 B3
A. B1
B. B2
C. B3
D. B4

B4

V
E. They all consume the same amount of
power.
Four identical light bulbs are
connected to a power supply as
B1
shown. Which light bulb
consumes the most power?
B2 B3
A. B1
B. B2
C. B3
D. B4

B4

V
E. They all consume the same amount of
power.
If two elements of a circuit are in parallel,
they must have the same
A. charge.
B. potential difference across them.
C. resistance.
D. potential difference across them and
the same current.
E. current.
If two elements of a circuit are in parallel,
they must have the same
A. charge.
B. potential difference across them.
C. resistance.
D. potential difference across them and
the same current.
E. current.
Which of the following relations among the
quantities in the figure is generally correct?
A.
I1R1 = I2R2
B.
I3R3 = I4R4
C. I1R1 = I4R4
D. I3R4 = I4R3
E.
I1R1 + I2R2 = e
Which of the following relations among the
quantities in the figure is generally correct?
A.
I1R1 = I2R2
B. I3R3 = I4R4
C. I1R1 = I4R4
D. I3R4 = I4R3
E.
I1R1 + I2R2 = e
Three resistors are placed in a simple circuit.
In which of the various configurations shown
do all three resistors carry the same current?
Three resistors are placed in a simple circuit.
In which of the various configurations shown
do all three resistors carry the same current?
The power delivered by the battery in the
circuit shown is
A. 2.5 W
B. 7.0 W
C. 3.1 W
D. 9.7 W
E. 5.3 W
The power delivered by the battery in the
circuit shown is
A. 2.5 W
B. 7.0 W
C. 3.1 W
D. 9.7 W
E. 5.3 W
Capacitance
A capacitor of capacitance C holds a charge
Q when the potential difference across the
plates is V. If the charge Q on the plates is
doubled to 2Q,
A. the capacitance becomes (1/2)V.
B. the capacitance becomes 2C.
C. the potential changes to (1/2)V.
D. the potential changes to 2V.
A capacitor of capacitance C holds a charge
Q when the potential difference across the
plates is V. If the charge Q on the plates is
doubled to 2Q,
A. the capacitance becomes (1/2)V.
B. the capacitance becomes 2C.
C. the potential changes to (1/2)V.
D. the potential changes to 2V.
If a capacitor of capacitance 2.0 µF is given
a charge of 1.0 mC, the potential difference
across the capacitor is
A. 0.50 kV.
B. 2.0 V.
C. 2.0 µV.
D. 0.50 V.
E. None of these is correct.
If a capacitor of capacitance 2.0 µF is given
a charge of 1.0 mC, the potential difference
across the capacitor is
A. 0.50 kV.
B. 2.0 V.
C. 2.0 µV.
D. 0.50 V.
E. None of these is correct.
An 80-nF capacitor is charged to a potential
of 500 V. How much charge accumulates on
each plate of the capacitor?
A. 4.0  10–4 C
B. 4.0  10–5 C
C. 4.0  10–10 C
D. 1.6  10–10 C
E. 1.6  10–7 C
An 80-nF capacitor is charged to a potential
of 500 V. How much charge accumulates on
each plate of the capacitor?
A. 4.0  10–4 C
B. 4.0  10–5 C
C. 4.0  10–10 C
D. 1.6  10–10 C
E. 1.6  10–7 C
Doubling the potential difference across a
capacitor
A. doubles its capacitance.
B. halves its capacitance.
C. quadruples the charge stored on the
capacitor.
D. halves the charge stored on the
capacitor.
E. does not change the capacitance of the
capacitor.
Doubling the potential difference across a
capacitor
A. doubles its capacitance.
B. halves its capacitance.
C. quadruples the charge stored on the
capacitor.
D. halves the charge stored on the
capacitor.
E. does not change the capacitance of
the capacitor.
Several different capacitors are hooked
across a DC battery in parallel. The charge
on each capacitor is
A. directly proportional to its
capacitance.
B. inversely proportional to its
capacitance.
C. independent of its capacitance.
Several different capacitors are hooked
across a DC battery in parallel. The charge
on each capacitor is
A. directly proportional to its
capacitance.
B. inversely proportional to its
capacitance.
C. independent of its capacitance.
Several different capacitors are hooked
across a DC battery in parallel. The voltage
across each capacitor is
A. directly proportional to its
capacitance.
B. inversely proportional to its
capacitance.
C. independent of its capacitance.
Several different capacitors are hooked
across a DC battery in parallel. The voltage
across each capacitor is
A. directly proportional to its
capacitance.
B. inversely proportional to its
capacitance.
C. independent of its
capacitance.
Several different capacitors are hooked
across a DC battery in series. The charge on
each capacitor is
A. directly proportional to its
capacitance.
B. inversely proportional to its
capacitance.
C. independent of its capacitance.
Several different capacitors are hooked
across a DC battery in series. The charge on
each capacitor is
A. directly proportional to its
capacitance.
B. inversely proportional to its
capacitance.
C. independent of its
capacitance.
Several different capacitors are hooked
across a DC battery in series. The voltage
across each capacitor is
A. directly proportional to its
capacitance.
B. inversely proportional to its
capacitance.
C. independent of its capacitance.
Several different capacitors are hooked
across a DC battery in series. The voltage
across each capacitor is
A. directly proportional to its
capacitance.
B. inversely proportional to its
capacitance.
C. independent of its capacitance.