Question 1

If two equipotent planes differ in potential by 1.0 volt,and the electric field between them is 20 N/C,what is the separation of the planes?

Accepted Answer

A)  20 cm 
B)  0.050 cm 
C)  5.0 cm 
D)  2.0 cm 
E)  4.0 cm 
A)  20 cm 
B)  0.050 cm 
C)  5.0 cm 
D)  2.0 cm 
E)  4.0 cm

Question 2

A parallel plate capacitor with circular plates having radius 0.07 m and a dielectric with constant 2.2.If it is desired to store 12 $\times$ 10-6 J in this capacitor,what must the separation distance be for a voltage of 1.5 kV?

Accepted Answer

A)  2.8 cm 
B)  5.5 cm 
C)  1.3 cm 
D)  0.90 cm 
E)  1.4 cm 
A)  2.8 cm 
B)  5.5 cm 
C)  1.3 cm 
D)  0.90 cm 
E)  1.4 cm

Question 3

A pair of parallel conducting plates have potentials of -17 V and 55 V,respectively.An electron is ejected from the plate at potential -17 V and travels to the plate at 55 V.What is the change in the electron's potential energy as it makes this journey?

Accepted Answer

A)  6.1 $\times$ 10-18 J 
B)  -6.1 $\times$ 10-18 J 
C)  1.2 $\times$ 10-17 J 
D)  -1.2 $\times$ 10-17 J 
A)  6.1 $\times$ 10-18 J 
B)  -6.1 $\times$ 10-18 J 
C)  1.2 $\times$ 10-17 J 
D)  -1.2 $\times$ 10-17 J

Question 4

If helium nuclei and protons are each accelerated from rest through the same potential difference V,which gets the greatest kinetic energy and by what factor is it greater?

Accepted Answer

A)  the protons get twice as much kinetic energy 
B)  the helium nuclei get twice as much kinetic energy 
C)  they both get the same kinetic energy 
D)  the protons get four times as much kinetic energy 
E)  the helium nuclei get four times as much kinetic energy 
A)  the protons get twice as much kinetic energy 
B)  the helium nuclei get twice as much kinetic energy 
C)  they both get the same kinetic energy 
D)  the protons get four times as much kinetic energy 
E)  the helium nuclei get four times as much kinetic energy

Question 5

A parallel plate capacitor has plates each of area 100 cm2 and with separation 0.25 mm.If this capacitor is charged with 25 pC,what is the average charge density on the positive plate?

Accepted Answer

A)  400 $\mu$C/m2 
B)  40 $\times$ 10-12 C/m2 
C)  25 pC/m2 
D)  2.5 nC/m2 
E)  8.8 $\times$ 10-12 C/m2 
A)  400 $\mu$C/m2 
B)  40 $\times$ 10-12 C/m2 
C)  25 pC/m2 
D)  2.5 nC/m2 
E)  8.8 $\times$ 10-12 C/m2

Question 6

Three point charges, q1 = 2.0 $\mu$C, q2 = 2.0 $\mu$C, and q3 = -1.0 $\mu$C,are located at the vertices of an equilateral triangle of side length 30 cm.What is the potential energy of this arrangement?

Accepted Answer

A)  0.24 J 
B)  0.12 J 
C)  -0.24 J 
D)  -0.12 J 
E)  0 
A)  0.24 J 
B)  0.12 J 
C)  -0.24 J 
D)  -0.12 J 
E)  0

Question 7

A conducting sphere of radius 20 cm has a charge Q placed on it producing a field of magnitude E0 at its surface.More charge is added to the surface until the magnitude of the field at the surface is 2 E0.If the potential at the surface was V0 when the field was E0,what is the potential when the field is 2 E0?

Accepted Answer

A)  V0/2 
B)  2 V0 
C)  4 V0 
D)  5 V0 
E)  16 V0 
A)  V0/2 
B)  2 V0 
C)  4 V0 
D)  5 V0 
E)  16 V0

Question 8

At a given location in space,the potential is known to be greater when one moves in any direction.To be more specific,no matter which direction one goes,a small step in that direction results in an increase in the potential by the same amount.This means that the Electric field at this location is

Accepted Answer

A)  Can take on any value at all. 
B)  Zero 
C)  Negative 
D)  Positive 
A)  Can take on any value at all. 
B)  Zero 
C)  Negative 
D)  Positive

Question 9

A parallel plate capacitor is attached to a voltage source providing 12 V.When an insulator of dielectric constant 6.0 is then used to fill the air space between the capacitor plates,what happens to the surface charge density on the plates if the voltage source is still attached?

Accepted Answer

A)  it increases by a factor of 6.0 
B)  it increases by a factor of 2.0 
C)  it decreases by a factor of 6.0 
D)  it decreases by a factor of 2.0 
E)  it stays the same 
A)  it increases by a factor of 6.0 
B)  it increases by a factor of 2.0 
C)  it decreases by a factor of 6.0 
D)  it decreases by a factor of 2.0 
E)  it stays the same

Question 10

Doubling both charges changes the potential energy for a pair of point charges by a factor of

Accepted Answer

A)  2. 
B)  4. 
C)  1/2. 
D)  1/4. 
E)  1 (no change). 
A)  2. 
B)  4. 
C)  1/2. 
D)  1/4. 
E)  1 (no change).

Question 11

If the area of the plates of a parallel plate capacitor is tripled and the plate separation is halved,by what factor does the capacitance change?

Accepted Answer

A)  it triples 
B)  it doubles 
C)  it increases by a factor of 6 
D)  it increases 1.5 times 
E)  it decreases to 2/3 the original 
A)  it triples 
B)  it doubles 
C)  it increases by a factor of 6 
D)  it increases 1.5 times 
E)  it decreases to 2/3 the original

Question 12

To store 80 mJ of energy in a 100 $\mu$F capacitor,what voltage is necessary?

Accepted Answer

A)  10 V 
B)  45 V 
C)  4.0 V 
D)  40 V 
E)  more than 120 V 
A)  10 V 
B)  45 V 
C)  4.0 V 
D)  40 V 
E)  more than 120 V

Question 13

A parallel plate capacitor has plates each of area 100 cm2 and with separation 0.25 mm.What is its capacitance?

Accepted Answer

A)  40 nC 
B)  0.35 nC 
C)  4.4 $\mu$F 
D)  88 pdf 
E)  88 $\mu$F 
A)  40 nC 
B)  0.35 nC 
C)  4.4 $\mu$F 
D)  88 pdf 
E)  88 $\mu$F

Question 14

A parallel plate capacitor with an air dielectric is attached to a voltage source and charged.The voltage source is removed,and then the plates are separated to double their previous distance.What happens to the energy stored by the capacitor when the plates are separated?

Accepted Answer

A)  it doubles 
B)  it quadruples 
C)  it halves 
D)  it is diminished by a factor of 4 
E)  it stays the same 
A)  it doubles 
B)  it quadruples 
C)  it halves 
D)  it is diminished by a factor of 4 
E)  it stays the same

Question 15

If the plate area,plate separation,and dielectric constant all are doubled for a parallel plate capacitor,what happens to the capacitance?

Accepted Answer

A)  it stays the same 
B)  it doubles 
C)  it quadruples 
D)  it halves 
E)  it quarters 
A)  it stays the same 
B)  it doubles 
C)  it quadruples 
D)  it halves 
E)  it quarters

Question 16

A pair of electric charges has a positive potential energy.This implies that

Accepted Answer

A)  The charges have the same sign 
B)  Both charges are positive 
C)  Both charges are negative 
D)  The charges have opposite signs 
A)  The charges have the same sign 
B)  Both charges are positive 
C)  Both charges are negative 
D)  The charges have opposite signs

Question 17

What area plates would a parallel plate 1.0 F capacitor have with a plate separation of 0.10 mm and a dielectric of constant 10?

Accepted Answer

A)  1000 cm2 
B)  5500 cm2 
C)  130 m2 
D)  1.1 $\times$ 106 m2 
E)  4.4 $\times$ 109 m2 
A)  1000 cm2 
B)  5500 cm2 
C)  130 m2 
D)  1.1 $\times$ 106 m2 
E)  4.4 $\times$ 109 m2

Question 18

A parallel plate capacitor is charged to 12 V and the voltage source is then disconnected.When the air space between the plates is then filled with a dielectric of constant 6.0,what is the resulting voltage between the plates?

Accepted Answer

A)  72 V 
B)  12 V 
C)  6.0 V 
D)  2.0 V 
E)  none of these choices are correct 
A)  72 V 
B)  12 V 
C)  6.0 V 
D)  2.0 V 
E)  none of these choices are correct

Question 19

If electrons are accelerated from rest in an electron gun by sending them through a potential difference of 11.0 kV,what is the resulting kinetic energy of each electron?

Accepted Answer

A)  11.0 kJ 
B)  1.00 $\times$ 10-19 J 
C)  1.45 $\times$ 10-23 J 
D)  11.0 mJ 
E)  1.76 $\times$ 10-15 J 
A)  11.0 kJ 
B)  1.00 $\times$ 10-19 J 
C)  1.45 $\times$ 10-23 J 
D)  11.0 mJ 
E)  1.76 $\times$ 10-15 J

Question 20

If 500 electrons are placed on a conducting sphere of radius 10 $\mu$m, what is the potential at its surface?

Accepted Answer

A)  100 V 
B)  -10,000 V 
C)  32 V 
D)  -72 mV 
E)  -72 V 
A)  100 V 
B)  -10,000 V 
C)  32 V 
D)  -72 mV 
E)  -72 V

Exam 17: Electric Potential

If two equipotent planes differ in potential by 1.0 volt,and the electric field between them is 20 N/C,what is the separation of the planes?

A parallel plate capacitor with circular plates having radius 0.07 m and a dielectric with constant 2.2.If it is desired to store 12 ×\times× 10-6 J in this capacitor,what must the separation distance be for a voltage of 1.5 kV?

A pair of parallel conducting plates have potentials of -17 V and 55 V,respectively.An electron is ejected from the plate at potential -17 V and travels to the plate at 55 V.What is the change in the electron's potential energy as it makes this journey?

If helium nuclei and protons are each accelerated from rest through the same potential difference V,which gets the greatest kinetic energy and by what factor is it greater?

A parallel plate capacitor has plates each of area 100 cm2 and with separation 0.25 mm.If this capacitor is charged with 25 pC,what is the average charge density on the positive plate?

Three point charges, q1 = 2.0 μ\muμ C, q2 = 2.0 μ\muμ C, and q3 = -1.0 μ\muμ C,are located at the vertices of an equilateral triangle of side length 30 cm.What is the potential energy of this arrangement?

At a given location in space,the potential is known to be greater when one moves in any direction.To be more specific,no matter which direction one goes,a small step in that direction results in an increase in the potential by the same amount.This means that the Electric field at this location is

A parallel plate capacitor is attached to a voltage source providing 12 V.When an insulator of dielectric constant 6.0 is then used to fill the air space between the capacitor plates,what happens to the surface charge density on the plates if the voltage source is still attached?

Doubling both charges changes the potential energy for a pair of point charges by a factor of

If the area of the plates of a parallel plate capacitor is tripled and the plate separation is halved,by what factor does the capacitance change?

To store 80 mJ of energy in a 100 μ\muμ F capacitor,what voltage is necessary?

A parallel plate capacitor has plates each of area 100 cm2 and with separation 0.25 mm.What is its capacitance?

A parallel plate capacitor with an air dielectric is attached to a voltage source and charged.The voltage source is removed,and then the plates are separated to double their previous distance.What happens to the energy stored by the capacitor when the plates are separated?

If the plate area,plate separation,and dielectric constant all are doubled for a parallel plate capacitor,what happens to the capacitance?

A pair of electric charges has a positive potential energy.This implies that

What area plates would a parallel plate 1.0 F capacitor have with a plate separation of 0.10 mm and a dielectric of constant 10?

A parallel plate capacitor is charged to 12 V and the voltage source is then disconnected.When the air space between the plates is then filled with a dielectric of constant 6.0,what is the resulting voltage between the plates?

If electrons are accelerated from rest in an electron gun by sending them through a potential difference of 11.0 kV,what is the resulting kinetic energy of each electron?

If 500 electrons are placed on a conducting sphere of radius 10 μ\muμ m, what is the potential at its surface?

Introduction

Force

Acceleration and Newtons Second Law of Motion

Motion With Constant Acceleration

Circular Motion

Conservation of Energy

Linear Momentum

Torque and Angular Momentum

Fluids

Elasticity and Oscillations

Waves

Sound

Temperature and the Ideal Gas

Heat

Thermodynamics

Electric Forces and Fields

Electric Current and Circuits

Magnetic Forces and Fields

Electromagnetic Induction

Alternating Current

Electromagnetic Waves

Reflection and Refraction of Light

Optical Instruments

Interference and Diffraction

Relativity

Early Quantum Physics and the Photon

Quantum Physics

Nuclear Physics

Particle Physics

Filters

A parallel plate capacitor with circular plates having radius 0.07 m and a dielectric with constant 2.2.If it is desired to store 12 $\times$ 10^-6 J in this capacitor,what must the separation distance be for a voltage of 1.5 kV?

A parallel plate capacitor has plates each of area 100 cm² and with separation 0.25 mm.If this capacitor is charged with 25 pC,what is the average charge density on the positive plate?

Three point charges, q₁ = 2.0 $\mu$ C, q₂ = 2.0 $\mu$ C, and q₃ = -1.0 $\mu$ C,are located at the vertices of an equilateral triangle of side length 30 cm.What is the potential energy of this arrangement?

To store 80 mJ of energy in a 100 $\mu$ F capacitor,what voltage is necessary?

A parallel plate capacitor has plates each of area 100 cm² and with separation 0.25 mm.What is its capacitance?

If 500 electrons are placed on a conducting sphere of radius 10 $\mu$ m, what is the potential at its surface?