A point charge {image} is placed at the origin. A second charge, {image} , is placed on the {image} axis at {image} . If {image} , what is the magnitude of the electrostatic force on a third point charge, {image} , placed on the {image} axis at {image} ?

1
A point charge image is placed at the origin. A
second charge, image , is placed on the image
axis at image . If image , what is the
magnitude of the electrostatic force on a third
point charge, image , placed on the image
axis at image ?

1. image
2. image
3. image
4. image
5. image

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2
A point charge image is placed on the image
axis at image , and a second charge image is
placed on the image axis at image . What is
the magnitude of the electric force on a third
charge image placed on the image axis at
image ?

1. image
2. image
3. image
4. image
5. image

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3
Three identical point charges image are placed
at the vertices of an equilateral triangle
(length of each side 2.4 m). If image , what
is the magnitude of the electrostatic force on
any one of the charges?

1. image
2. image
3. image
4. image
5. image

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4
Three point charges, two positive and one
negative, each having a magnitude of image are
placed at the vertices of an equilateral triangle
(28 cm on a side). What is the magnitude of the
electrostatic force on one of the positive
charges?

1. image
2. image
3. image
4. image
5. image

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5
A charge of image is placed on the image axis
at image and a image charge is placed on the
image axis at image . If both charges are
held fixed, what is the magnitude of the initial
acceleration of an electron released from rest at
the origin?

1. image
2. image
3. image
4. image
5. image

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6
A image charge is positioned on the image
axis at image . Where should a image charge
be placed to produce a net electric field of zero
at the origin?

1. image
2. image
3. image
4. image
5. image

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7
Each of two small non-conducting spheres is
charged positively, the combined charge being
image . When the two spheres are 70 cm apart,
each sphere is repelled from the other by a force
of magnitude 4.0 N. Determine the magnitude of
the smaller of the two charges.

1. image
2. image
3. image
4. image
5. image

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8
A particle ( image , image ) is released from
rest when it is image from a second particle
image . Determine the magnitude of the initial
acceleration of the 54-g particle.

1. image
2. image
3. image
4. image
5. image

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9
A charge of image is placed on the image axis
at image . A second charge of image is placed
on the image axis at image . What is the
magnitude of the electrostatic force on a third
charge of image placed on the image axis at
image ?

1. image
2. image
3. image
4. image
5. image

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10
Two identical pith balls supported by insulating
threads hang side by side and close together, as
shown below. applet

1. some of the field lines leaving the positively
   charged pith ball end on the neutral pith ball
2. all field lines leaving the positively charged
   pith ball end on the neutral pith ball
3. none of the field lines leaving the positively
   charged pith ball end on the neutral pith ball
4. positive charge is transferred along the field
   lines until both balls have equal charges
5. positive charge is transferred along the field
   lines until both balls hang along vertical lines

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11
If image , image , and image in the figure,
what is the magnitude of the electric field at
point P? applet

1. image
2. image
3. image
4. image
5. image

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12
If image , image , image , image , and
image in the figure, what is the magnitude of
the total electric force on image ? applet

1. image
2. image
3. image
4. image
5. image

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13
A uniform linear charge of image is distributed
along the image axis from image to image .
Which of the following integrals is correct for
the magnitude of the electric field at image on
the image axis?

1. image
2. image
3. image
4. image
5. none of these

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14
A image charge is distributed uniformly along
the image axis from image to image . Which
of the following integrals is correct for the
image component of the electric field at
image on the image axis?

1. image
2. image
3. image
4. image
5. none of these

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15
Which one of the diagrams below is not a possible
electric field configuration for a region of
space which does not contain any charges?

1. applet
2. applet
3. applet
4. applet
5. applet

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16
A negatively charged particle is moving in the
y-direction when it enters a region with a
uniform electric field pointing in the
x-direction. Which of the diagrams below shows
its path while it is in the region where the
electric field exists? The region with the field
is the region between the plates bounding each
figure. The field lines always point to the
right. The x-direction is to the right the
y-direction is up.

1. applet
2. applet
3. applet
4. applet
5. applet

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17
The symbol image appears in Coulomb's law
because we use independently defined units for
_____ .

1. force, distance and electric charge
2. force
3. distance
4. force and distance
5. charge and distance

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18
A uniform linear charge of image is distributed
along the image axis from image to image .
Which of the following integrals is correct for
the image component of the electric field at
image on the image axis?

1. image
2. image
3. image
4. image
5. none of these

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19
Rubber rods charged by rubbing with cat fur repel
each other. Glass rods charged by rubbing with
silk repel each other. A rubber rod and a glass
rod charged respectively as above attract each
other. What is a possible explanation?

1. A rubber rod and a glass rod charged this way
   have opposite charges on them.
2. Any two rubber rods charged this way have
   opposite charges on them.
3. Any two glass rods charged this way have opposite
   charges on them.
4. All rubber rods always have an excess of positive
   charge on them.
5. All glass rods always have an excess of negative
   charge on them.

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20
A positive charge image is placed in the field
created by two other charges image and image
, each a distance image away from image .
What is the direction of the acceleration of
image ?

1. the direction determined by the vector sum of the
   electric fields of image and image
2. toward image or image whichever charge has
   smaller magnitude
3. toward image or image whichever charge has
   greater magnitude
4. toward the negative charge if image and image
   are of opposite sign
5. toward the positive charge if image and image
   are of opposite sign

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21
A uniformly charged rod (length 2.1 m, charge
per unit length 2.3 nC/m) is bent to form a
semicircle. What is the magnitude of the electric
field at the center of the circle?

1. image
2. image
3. image
4. image
5. image

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22
A uniformly charged rod (length 2.1 m, charge
per unit length 4.8 nC/m) is bent to form one
quadrant of a circle. What is the magnitude of
the electric field at the center of the circle?

1. image
2. image
3. image
4. image
5. image

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23
Charge image is distributed uniformly along a
semicircle of radius image . Which formula
below gives the correct magnitude of the force on
a particle of charge image located at the
center of the circle?

1. image
2. image
3. image
4. image
5. image

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24
Charge image is distributed uniformly along a
semicircle of radius image . Which formula
below gives the correct magnitude of the electric
field at the center of the circle?

1. image
2. image
3. image
4. image
5. image

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25
A particle ( image , image ) moves in a
uniform electric field of 69 N/C in the positive
x direction. At image , the particle is moving
30 m/s in the positive x direction and is passing
through the origin. Determine the maximum
distance beyond image the particle travels in
the positive x direction.

1. image
2. image
3. image
4. image
5. image

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26
A particle ( image , image ) moves in a
uniform electric field of 57 N/C in the positive
x direction. At image , the particle is moving
25 m/s in the positive x direction and is passing
through the origin. How far is the particle from
the origin at image ?

1. image
2. image
3. image
4. image
5. image

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27
A particle ( image , image ) has a velocity
of 18 m/s in the positive x direction when it
first enters a region where the electric field is
uniform (60 N/C in the positive y direction).
What is the speed of the particle 4.5 s after it
enters this region?

1. image
2. image
3. image
4. image
5. image

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28
A charge (uniform linear density image ) is
distributed along the image axis from image
to image . Determine the magnitude of the
electric field at a point on the image axis
with image .

1. image
2. image
3. image
4. image
5. image

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29
A particle (mass 4.5 g, charge 33 mC) moves
in a region of space where the electric field is
uniform and is given by image , image . If
the position and velocity of the particle at
image are given by image and image ,
image , what is the distance from the origin to
the particle at image ?

1. image
2. image
3. image
4. image
5. image

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30
A charge image is placed on the image axis at
image . A second charge image is located at
the origin. If image and image , what is the
magnitude of the electric field on the image
axis at image ?

1. image
2. image
3. image
4. image
5. image

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31
If image , image , image , and image ,
what is the magnitude of the electric field at
point P in the figure? applet

1. image
2. image
3. image
4. image
5. image

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32
A particle (mass 3.8 g, charge 88 mC) moves
in a region of space where the electric field is
uniform and is given by image , image . If
the velocity of the particle at image is given
by image , image , what is the speed of the
particle at image ?

1. image
2. image
3. image
4. image
5. image

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33
If image , image , image , and image ,
what is the magnitude of the electric field at
point P? applet

1. image
2. image
3. image
4. image
5. image

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34
If image and image , what is the magnitude of
the electrostatic force on any one of the charges
shown? applet

1. image
2. image
3. image
4. image
5. image

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35
Three pith balls supported by insulating threads
hang from a support. We know that ball X is
positively charged. When ball X is brought near
balls Y and Z without touching them, it attracts
Y and repels Z. What can we conclude?

1. Y is negatively charged or neutral (has no net
   charge.)
2. Y has a negative charge.
3. Z has a negative charge.
4. Y has a positive charge.
5. Z is neutral (has no net charge.)

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36
If image , image , image , image , and
image in the figure, what is the magnitude of
the total electric force on image ? applet

1. image
2. image
3. image
4. image
5. image

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37
If you rub an inflated balloon against your hair,
the two materials attract each other, as shown in
the figure below. image The amount of charge
present in the system of the balloon and your
hair after rubbing is _____ the amount of charge
present before rubbing.

1. less than
2. the same as
3. more than

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38
Three objects are brought close to each other,
two at a time. When objects A and B are brought
together, they attract. When objects B and C are
brought together, they repel. From this, we
conclude that _____.

1. objects A and C possess charges of the same sign
2. objects A and C possess charges of opposite sign
3. all three of the objects possess charges of the
   same sign
4. one of the objects is neutral
5. we need to perform additional experiments to
   determine information about the charges on the
   objects

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39
Object A has a charge of image and object B has
a charge of image Which statement is true about
the electric forces on the objects?

1. image
2. image
3. image
4. image
5. image
6. image

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40
Rank the magnitude of the electric field at
points A, B, and C shown in the figure below
(greatest magnitude first). image

1. A gt B gt C
2. A gt C gt B
3. B gt A gt C
4. B gt C gt A
5. C gt A gt B
6. C gt B gt A

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