Question 1

Which of the following materials has the highest dielectric constant?

Accepted Answer

A) air 
B) Mylar 
C) paper 
D) Pyrex glass 
E) water 
A) air 
B) Mylar 
C) paper 
D) Pyrex glass 
E) water E

Question 2

A 15-μF capacitor is charged to 40 V and then connected across an initially uncharged 25-μF capacitor. What is the final potential difference across the 25-μF capacitor?

Accepted Answer

A) 12 V 
B) 18 V 
C) 15 V 
D) 21 V 
E) 24 V 
A) 12 V 
B) 18 V 
C) 15 V 
D) 21 V 
E) 24 V C

Question 3

A 6.0-μF capacitor charged to 50 V and a 4.0-μF capacitor charged to 34 V are connected to each other, with the two positive plates connected and the two negative plates connected. What is the total energy stored in the 6.0-μF capacitor at equilibrium?

Accepted Answer

A) 6.1 mJ 
B) 5.7 mJ 
C) 6.6 mJ 
D) 7.0 mJ 
E) 3.8 mJ 
A) 6.1 mJ 
B) 5.7 mJ 
C) 6.6 mJ 
D) 7.0 mJ 
E) 3.8 mJ B

Question 4

A parallel plate capacitor of capacitance C0 has plates of area A with separation d between them. When it is connected to a battery of voltage V0, it has charge of magnitude Q0 on its plates. It is then disconnected from the battery and the space between the plates is filled with a material of dielectric constant 3. After the dielectric is added, the magnitudes of the charge on the plates and the potential difference between them are

Accepted Answer

A)    Q0,   V0. 
B) Q0,   V0. 
C) Q0, V0. 
D) Q0, 3V0. 
E) 3Q0, 3V0. 
A)    Q0,   V0. 
B) Q0,   V0. 
C) Q0, V0. 
D) Q0, 3V0. 
E) 3Q0, 3V0.

Question 5

What is the equivalent capacitance of the combination shown?

Accepted Answer

A) 20 μF 
B) 90 μF 
C) 22 μF 
D) 4.6 μF 
E) 67 μF 
A) 20 μF 
B) 90 μF 
C) 22 μF 
D) 4.6 μF 
E) 67 μF

Question 6

What is the total energy stored in the group of capacitors shown if the charge on the 30-μF capacitor is 0.90 mC?

Accepted Answer

A) 29 mJ 
B) 61 mJ 
C) 21 mJ 
D) 66 mJ 
E) 32 mJ 
A) 29 mJ 
B) 61 mJ 
C) 21 mJ 
D) 66 mJ 
E) 32 mJ

Question 7

What total energy is stored in the group of capacitors shown if the potential difference Vab is equal to 50 V?

Accepted Answer

A) 48 mJ 
B) 27 mJ 
C) 37 mJ 
D) 19 mJ 
E) 10 mJ 
A) 48 mJ 
B) 27 mJ 
C) 37 mJ 
D) 19 mJ 
E) 10 mJ

Question 8

A 30-μF capacitor is charged to 40 V and then connected across an initially uncharged 20-μF capacitor. What is the final potential difference across the 30-μF capacitor?

Accepted Answer

A) 15 V 
B) 24 V 
C) 18 V 
D) 21 V 
E) 40 V 
A) 15 V 
B) 24 V 
C) 18 V 
D) 21 V 
E) 40 V

Question 9

A 4.0-mF capacitor initially charged to 50 V and a 6.0-mF capacitor charged to 30 V are connected to each other with the positive plate of each connected to the negative plate of the other. What is the final charge on the 6.0-mF capacitor?

Accepted Answer

A) 20 mC 
B) 8.0 mC 
C) 10 mC 
D) 12 mC 
E) 230 mC 
A) 20 mC 
B) 8.0 mC 
C) 10 mC 
D) 12 mC 
E) 230 mC

Question 10

A 0.16-pF parallel-plate capacitor is charged to 10 V. Then the battery is disconnected from the capacitor. When 1.00 × 107 electrons are now placed on the negative plate of the capacitor, the voltage between the plates changes by

Accepted Answer

A) −5.0 V. 
B) −1.1 V. 
C) 0 V. 
D) +1.1 V. 
E) +5.0 V. 
A) −5.0 V. 
B) −1.1 V. 
C) 0 V. 
D) +1.1 V. 
E) +5.0 V.

Question 11

Determine the equivalent capacitance of the combination shown when C = 24 μF.

Accepted Answer

A) 20 μF 
B) 36 μF 
C) 16 μF 
D) 45 μF 
E) 27 μF 
A) 20 μF 
B) 36 μF 
C) 16 μF 
D) 45 μF 
E) 27 μF

Question 12

A parallel plate capacitor of capacitance C0 has plates of area A with separation d between them. When it is connected to a battery of voltage V0, it has charge of magnitude Q0 on its plates. While it is connected to the battery the space between the plates is filled with a material of dielectric constant 3. After the dielectric is added, the magnitude of the charge on the plates and the potential difference between them are what?

Accepted Answer

A)    Q0,   V0 
B) Q0,   V0 
C) Q0, V0 
D) 3Q0, V0 
E) 3Q0, 3V0 
A)    Q0,   V0 
B) Q0,   V0 
C) Q0, V0 
D) 3Q0, V0 
E) 3Q0, 3V0

Question 13

Is it feasible to construct an air-filled parallel-plate capacitor that has its two plates separated by 0.10 mm and has a capacitance of 1.0 F? Why or why not?

Accepted Answer

No. Each p

Question 14

Regarding the Earth and a cloud layer 800 m above the Earth as the "plates" of a capacitor, calculate the capacitance if the cloud layer has an area of 1.0 km2. If an electric field of 2.0 × 106 N/C makes the air break down and conduct electricity (lightning), what is the maximum charge the cloud can hold?

Accepted Answer

Question 15

A 30-μF capacitor is charged to an unknown potential V0 and then connected across an initially uncharged 10-μF capacitor. If the final potential difference across the 10-μF capacitor is 20 V, determine V0.

Accepted Answer

A) 13 V 
B) 27 V 
C) 20 V 
D) 29 V 
E) 60 V 
A) 13 V 
B) 27 V 
C) 20 V 
D) 29 V 
E) 60 V

Question 16

Two spheres are made of conducting material. Sphere #2 has twice the radius of Sphere #1. What is the ratio of the capacitance of Sphere #2 to the capacitance of Sphere #1?

Accepted Answer

A) 1, since all conducting spheres have the same capacitance. 
B) 2 
C) 4 
D) 8 
E) A single sphere has no capacitance since a second concentric spherical shell is necessary to make a spherical capacitor.Thus, none of the answers above is correct. 
A) 1, since all conducting spheres have the same capacitance. 
B) 2 
C) 4 
D) 8 
E) A single sphere has no capacitance since a second concentric spherical shell is necessary to make a spherical capacitor.Thus, none of the answers above is correct.

Question 17

What is the equivalent capacitance of the combination shown?

Accepted Answer

A) 29 μF 
B) 10 μF 
C) 40 μF 
D) 25 μF 
E) 6.0 μF 
A) 29 μF 
B) 10 μF 
C) 40 μF 
D) 25 μF 
E) 6.0 μF

Question 18

A parallel plate capacitor is connected to a battery and charged to voltage V. Leah says that the charge on the plates will decrease if the distance between the plates is increased while they are still connected to the battery. Gertie says that the charge will remain the same. Which one, if either, is correct, and why?

Accepted Answer

A) Gertie, because the maximum voltage is determined by the battery. 
B) Gertie, because the capacitance of the capacitor does not change. 
C) Leah, because the capacitance decreases when the plate separation is increased. 
D) Leah, because the capacitance increases when the plate separation is increased. 
E) Neither, because the charge increases when the plate separation is increased. 
A) Gertie, because the maximum voltage is determined by the battery. 
B) Gertie, because the capacitance of the capacitor does not change. 
C) Leah, because the capacitance decreases when the plate separation is increased. 
D) Leah, because the capacitance increases when the plate separation is increased. 
E) Neither, because the charge increases when the plate separation is increased.

Question 19

Which of the following statements is incorrect?

Accepted Answer

A) Capacitance is always positive. 
B) The symbol for potential difference between the plates of a capacitor is   . 
C) Water is a polar molecule. 
D) When a dielectric is placed in a capacitor it serves to reduce the electric field. 
E) Nonpolar molecules cannot be used for dielectric material in a capacitor. 
A) Capacitance is always positive. 
B) The symbol for potential difference between the plates of a capacitor is   . 
C) Water is a polar molecule. 
D) When a dielectric is placed in a capacitor it serves to reduce the electric field. 
E) Nonpolar molecules cannot be used for dielectric material in a capacitor.

Question 20

Determine the equivalent capacitance of the combination shown when C = 45 μF.

Accepted Answer

A) 28 μF 
B) 36 μF 
C) 52 μF 
D) 44 μF 
E) 23 μF 
A) 28 μF 
B) 36 μF 
C) 52 μF 
D) 44 μF 
E) 23 μF

Exam 27: Capacitors and Batteries

Which of the following materials has the highest dielectric constant?

A 15-μF capacitor is charged to 40 V and then connected across an initially uncharged 25-μF capacitor. What is the final potential difference across the 25-μF capacitor?

A 6.0-μF capacitor charged to 50 V and a 4.0-μF capacitor charged to 34 V are connected to each other, with the two positive plates connected and the two negative plates connected. What is the total energy stored in the 6.0-μF capacitor at equilibrium?

What is the equivalent capacitance of the combination shown?

What is the total energy stored in the group of capacitors shown if the charge on the 30-μF capacitor is 0.90 mC?

What total energy is stored in the group of capacitors shown if the potential difference Vab is equal to 50 V?

A 30-μF capacitor is charged to 40 V and then connected across an initially uncharged 20-μF capacitor. What is the final potential difference across the 30-μF capacitor?

A 4.0-mF capacitor initially charged to 50 V and a 6.0-mF capacitor charged to 30 V are connected to each other with the positive plate of each connected to the negative plate of the other. What is the final charge on the 6.0-mF capacitor?

A 0.16-pF parallel-plate capacitor is charged to 10 V. Then the battery is disconnected from the capacitor. When 1.00 × 107 electrons are now placed on the negative plate of the capacitor, the voltage between the plates changes by

Determine the equivalent capacitance of the combination shown when C = 24 μF.

Is it feasible to construct an air-filled parallel-plate capacitor that has its two plates separated by 0.10 mm and has a capacitance of 1.0 F? Why or why not?

A 30-μF capacitor is charged to an unknown potential V0 and then connected across an initially uncharged 10-μF capacitor. If the final potential difference across the 10-μF capacitor is 20 V, determine V0.

Two spheres are made of conducting material. Sphere #2 has twice the radius of Sphere #1. What is the ratio of the capacitance of Sphere #2 to the capacitance of Sphere #1?

What is the equivalent capacitance of the combination shown?

Which of the following statements is incorrect?

Determine the equivalent capacitance of the combination shown when C = 45 μF.

Getting Started

One-Dimensional Motion

Vectors

Two- and Three-Dimensional Motion

Newtons Laws of Motion

Applications of Newtons Laws of Motion

Gravity

Conservation of Energy

Energy in Nonisolated Systems

Systems of Particles and Conservation of Momentum

Collisions

Rotation I: Kinematics and Dynamics

Rotation II: a Conservation Approach

Static Equilibrium, Elasticity, and Fracture

Fluids

Oscillations

Traveling Waves

Superposition and Standing Waves

Temperature, Thermal Expansion, and Gas Laws

Kinetic Theory of Gases

Heat and the First Law of Thermodynamics

Entropy and the Second Law of Thermodynamics

Electric Forces

Electric Fields

Gausss Law

Electric Potential

Current and Resistance

Direct Current Dc Circuits

Magnetic Fields and Forces

Gausss Law for Magnetism and Amperes Law

Faradays Law of Induction

Inductors and Ac Circuits

Maxwells Equations and Electromagnetic Waves

Diffraction and Interference

Applications of the Wave Model

Reflection and Images Formed by Reflection

Refraction and Images Formed by Refraction

Relativity

Filters