Download Two flat parallel plates are d = 0.40 cm apart. The

Chapter 24: Capacitance
Section 24-1: Capacitance
Two flat parallel plates are d = 0.40 cm apart. The
potential difference between the plates is 360 V.
The electric field at the point P at the center is
approximately
A. 90 kN/C.
B. 180 N/C.
C. 0.9 kN/C.
D. Zero.
E. 3.6  105 N/C
Two flat parallel plates are d = 0.40 cm apart. The
potential difference between the plates is 360 V.
The electric field at the point P at the center is
approximately
A. 90 kN/C.
B. 180 N/C.
C. 0.9 kN/C.
D. Zero.
E. 3.6  105 N/C
Two large metallic plates are parallel to each other and
charged. The distance between the plates is d. The
potential difference between the plates is V. The
magnitude of the electric field E in the region between
the plates and away from the edges is given by
A. d/V.
B. V2/d.
C. d ∙V.
D. V/d2.
E. V/d.
Two large metallic plates are parallel to each other and
charged. The distance between the plates is d. The
potential difference between the plates is V. The
magnitude of the electric field E in the region between
the plates and away from the edges is given by
A. d/V.
B. V2/d.
C. d ∙V.
D. V/d2.
E. V/d .
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.
E. the potential does not change.
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.
E. the potential does not change.
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.
If the area of the plates of a parallel-plate
capacitor is doubled, the capacitance is
A. not changed.
B. doubled.
C. halved.
D. increased by a factor of 4.
E. decreased by a factor of 1/4.
If the area of the plates of a parallel-plate
capacitor is doubled, the capacitance is
A. not changed.
B. doubled.
C. halved.
D. increased by a factor of 4.
E. decreased by a factor of 1/4.
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
As the voltage in the circuit is increased (but not to
the breakdown voltage), the capacitance
A. increases.
B. decreases.
C. does not change.
As the voltage in the circuit is increased (but not to
the breakdown voltage), the capacitance
A. increases.
B. decreases.
C. does not change.
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.
If the area of the plates of a parallel plate
capacitor is halved and the separation
between the plates tripled, then by what
factor does the capacitance change?
A. It increases by a factor of 6.
B. It decreases by a factor of 2/3.
C. It decreases by a factor of 1/6.
D. It increases by a factor of 3/2.
E. It decreases by a factor of ½.
If the area of the plates of a parallel plate
capacitor is halved and the separation
between the plates tripled, then by what
factor does the capacitance change?
A. It increases by a factor of 6.
B. It decreases by a factor of 2/3.
C. It decreases by a factor of 1/6.
D. It increases by a factor of 3/2.
E. It decreases by a factor of ½.
Chapter 24: Capacitance
Section 24-2: The Storage of Electrical
Energy
Which of the following statements is false?
A. In the process of charging a capacitor, an electric field is
produced between its plates.
B. The work required to charge a capacitor can be thought
of as the work required to create the electric field
between its plates.
C. The energy density in the space between the plates of a
capacitor is directly proportional to the first power of the
electric field.
D. The potential difference between the plates of a
capacitor is directly proportional to the electric field.
E. None of these is false.
Which of the following statements is false?
A. In the process of charging a capacitor, an electric field is
produced between its plates.
B. The work required to charge a capacitor can be thought
of as the work required to create the electric field
between its plates.
C. The energy density in the space between the plates
of a capacitor is directly proportional to the first
power of the electric field.
D. The potential difference between the plates of a
capacitor is directly proportional to the electric field.
E. None of these is false.
Which of the following statements about a
parallel plate capacitor is false?
A. The two plates have equal charges of the
same sign.
B. The capacitor stores charges on the plates.
C. The capacitance is proportional to the area
of the plates.
D. The capacitance is inversely proportional to
the separation between the plates.
E. A charged capacitor stores energy.
Which of the following statements about a
parallel plate capacitor is false?
A. The two plates have equal charges of the
same sign.
B. The capacitor stores charges on the plates.
C. The capacitance is proportional to the area
of the plates.
D. The capacitance is inversely proportional to
the separation between the plates.
E. A charged capacitor stores energy.
If you increase the charge on a parallel-plate
capacitor from 3 µC to 9 µC and increase the plate
separation from 1 mm to 3 mm, but keep all other
properties the same, the energy stored in the
capacitor changes by a factor of
A. 27.
B. 9.
C. 3.
D. 8.
E. 1/3.
If you increase the charge on a parallel-plate
capacitor from 3 µC to 9 µC and increase the plate
separation from 1 mm to 3 mm, but keep all other
properties the same, the energy stored in the
capacitor changes by a factor of
A. 27.
B. 9.
C. 3.
D. 8.
E. 1/3.
The energy stored in a capacitor is directly
proportional to
A. the voltage across the capacitor.
B. the charge on the capacitor.
C. the reciprocal of the charge on the capacitor.
D. the square of the voltage across the
capacitor.
E. None of these is correct.
The energy stored in a capacitor is directly
proportional to
A. the voltage across the capacitor.
B. the charge on the capacitor.
C. the reciprocal of the charge on the capacitor.
D. the square of the voltage across the
capacitor.
E. None of these is correct.
A parallel plate capacitor is constructed using two
square metal sheets, each of side L = 10 cm. The
plates are separated by a distance d = 2 mm and a
voltage applied between the plates. The electric
field strength within the plates is E = 4000 V/m.
The energy stored in the capacitor is
A. 0.71 nJ.
B. 1.42 nJ.
C. 2.83 nJ.
D. 3.67 nJ.
E. Zero.
A parallel plate capacitor is constructed using two
square metal sheets, each of side L = 10 cm. The
plates are separated by a distance d = 2 mm and a
voltage applied between the plates. The electric
field strength within the plates is E = 4000 V/m.
The energy stored in the capacitor is
A. 0.71 nJ.
B. 1.42 nJ.
C. 2.83 nJ.
D. 3.67 nJ.
E. Zero.
Chapter 24: Capacitance
Section 24-3: Capacitors, Batteries and
Circuits, and Concept Check 24-1
A circuit consists of a capacitor, a battery, and a
switch, all connected in series. Initially, the switch
is open and the capacitor is uncharged. The
switch is then closed and the capacitor charges.
While the capacitor is charging, how does the net
charge within the battery change?
A. It increases.
B. It decreases.
C. It stays the same
A circuit consists of a capacitor, a battery, and a
switch, all connected in series. Initially, the switch
is open and the capacitor is uncharged. The
switch is then closed and the capacitor charges.
While the capacitor is charging, how does the net
charge within the battery change?
A. It increases.
B. It decreases.
C. It stays the same
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.
If C1 < C2 < C3 < C4 for the combination of
capacitors shown, the equivalent
capacitance is
A. less than C1.
B. more than C4.
C. between C1 and C4.
If C1 < C2 < C3 < C4 for the combination of
capacitors shown, the equivalent
capacitance is
A. less than C1.
B. more than C4.
C. between C1 and C4.
If C1 < C2 < C3 < C4 for the combination of
capacitors shown, the equivalent capacitance
is
A. less than C1.
B. more than C4.
C. between C1 and C4.
If C1 < C2 < C3 < C4 for the combination of
capacitors shown, the equivalent capacitance
is
A. less than C1.
B. more than C4.
C. between C1 and C4.
The equivalent capacitance of two
capacitors in series is
A. the sum of their capacitances.
B. the sum of the reciprocals of their
capacitances.
C. always greater than the larger of their
capacitances.
D. always less than the smaller of the
capacitances.
E. described by none of the above.
The equivalent capacitance of two
capacitors in series is
A. the sum of their capacitances.
B. the sum of the reciprocals of their
capacitances.
C. always greater than the larger of their
capacitances.
D. always less than the smaller of the
capacitances.
E. described by none of the above.
The equivalent capacitance of three
capacitors in series is
A. the sum of their capacitances.
B. the sum of the reciprocals of their
capacitances.
C. always greater than the larger of their
capacitances.
D. always less than the smaller of the
capacitances.
E. described by none of the above.
The equivalent capacitance of three
capacitors in series is
A. the sum of their capacitances.
B. the sum of the reciprocals of their
capacitances.
C. always greater than the larger of their
capacitances.
D. always less than the smaller of the
capacitances.
E. described by none of the above.
The equivalent capacitance of two
capacitors in parallel is
A. the sum of the reciprocals of their
capacitances.
B. the reciprocal of the sum of the reciprocals of
their capacitances.
C. always greater than the larger of their
capacitances.
D. always less than the smaller of the two
capacitances.
E. described by none of the above.
The equivalent capacitance of two
capacitors in parallel is
A. the sum of the reciprocals of their
capacitances.
B. the reciprocal of the sum of the reciprocals of
their capacitances.
C. always greater than the larger of their
capacitances.
D. always less than the smaller of the two
capacitances.
E. described by none of the above.
Chapter 24: Capacitance
Section 24-4: Dielectrics
The capacitance of a parallel-plate capacitor
A. is defined as the amount of work required to
move a charge from one plate to the other.
B. decreases if a dielectric is placed between its
plates.
C. is independent of the distance between the
plates.
D. has units of J/C.
E. is independent of the charge on the capacitor.
The capacitance of a parallel-plate capacitor
A. is defined as the amount of work required to
move a charge from one plate to the other.
B. decreases if a dielectric is placed between its
plates.
C. is independent of the distance between the
plates.
D. has units of J/C.
E. is independent of the charge on the
capacitor.
A capacitor is connected to
a battery as shown. When a
dielectric is inserted
between the plates of the
capacitor,
A. only the capacitance changes.
B. only the voltage across the capacitor changes.
C. only the charge on the capacitor changes.
D. both the capacitance and the voltage change.
E. both the capacitance and the charge change.
A capacitor is connected to
a battery as shown. When a
dielectric is inserted
between the plates of the
capacitor,
A. only the capacitance changes.
B. only the voltage across the capacitor changes.
C. only the charge on the capacitor changes.
D. both the capacitance and the voltage change.
E. both the capacitance and the charge
change.
Two identical
capacitors A and B are
connected across a
battery, as shown. If
mica (k = 5.4) is
inserted in B,
A. both capacitors will retain the same charge.
B. B will have the larger charge.
C. A will have the larger charge.
D. the potential difference across B will increase.
E. the potential difference across A will increase.
Two identical
capacitors A and B are
connected across a
battery, as shown. If
mica (k = 5.4) is
inserted in B,
A. both capacitors will retain the same charge.
B. B will have the larger charge.
C. A will have the larger charge.
D. the potential difference across B will increase.
E. the potential difference across A will increase.
If a dielectric is inserted between the plates
of a parallel-plate capacitor that is
connected to a 100-V battery, the
A. voltage across the capacitor decreases.
B. electric field between the plates decreases.
C. electric field between the plates increases.
D. charge on the capacitor plates decreases.
E. charge on the capacitor plates increases.
If a dielectric is inserted between the plates
of a parallel-plate capacitor that is
connected to a 100-V battery, the
A. voltage across the capacitor decreases.
B. electric field between the plates decreases.
C. electric field between the plates increases.
D. charge on the capacitor plates decreases.
E. charge on the capacitor plates
increases.
A charged capacitor has an initial electric field E0 and potential
difference V0 across its plates. Without connecting any source of
emf, you insert a dielectric (k > 1) slab between the plates to
produce an electric field Ed and a potential difference Vd across
the capacitor. The pair of statements that best represents the
relationships between the magnitude of the electric fields and
potential differences is
A. Ed > E0; Vd > V0
.
D. Ed < E0; Vd > V0.
B. Ed = E0; Vd > V0 .
E. Ed < E0; Vd < V0.
C. Ed > E0; Vd = V0.
A charged capacitor has an initial electric field E0 and potential
difference V0 across its plates. Without connecting any source of
emf, you insert a dielectric (k > 1) slab between the plates to
produce an electric field Ed and a potential difference Vd across
the capacitor. The pair of statements that best represents the
relationships between the magnitude of the electric fields and
potential differences is
A. Ed > E0; Vd > V0.
D. Ed < E0; Vd > V0.
B. Ed = E0; Vd > V0.
E. Ed < E0; Vd < V0.
C. Ed > E0; Vd = V0.
Chapter 24: Capacitance
Section 24-5: Molecular View of a
Dielectric, and Concept Check 24-2
Does the capacitance always increase when
a dielectric is inserted into the gap of a
capacitor?
A. Yes, it always increases.
B. No, it always decreases.
C. No, it may increase or decrease
depending on the dielectric constant of
the material.
Does the capacitance always increase when
a dielectric is inserted into the gap of a
capacitor?
A. Yes, it always increases.
B. No, it always decreases.
C. No, it may increase or decrease
depending on the dielectric constant of
the material.
An external electric field, E, is applied to a region
which contains a dielectric. Which of the following
statements is true?
A. The electric field within the dielectric is less than
E.
B. The dielectric produces an electric field in the
opposite direction to E.
C. The molecules in the dielectric become polarized.
D. The electric field will produce a torque on
molecules in the dielectric that have permanent
dipoles.
E. All the above statements are true.
An external electric field, E, is applied to a region
which contains a dielectric. Which of the following
statements is true?
A. The electric field within the dielectric is less than
E.
B. The dielectric produces an electric field in the
opposite direction to E.
C. The molecules in the dielectric become polarized.
D. The electric field will produce a torque on
molecules in the dielectric that have permanent
dipoles.
E. All the above statements are true.