PHYSICS

As used in the definition of electric field, a "test charge"

(it is none of the above.... I think we typically assume a test charge is a proton.)

If the electric field is in the positive x direction and has a magnitude of E = C x^2 , then the electric potential V is given by :

- C x^3 /3

A particle with a charge of 5.5 x 10 ^-8 C is 3.5 cm from a particle with a charge of -2.3 x 10 ^-8 C. The potential energy of this two particle system, relative to the potential energy at infinite separation, is :

-3.2 x 10^-4

Three particles lie on the x axis : particle 1, with a charge of 1x 10 ^ -8 C is at x = 1 cm, particle 2, with a charge of 2 x10 ^-8 C is at x=2 cm, and particle 3, with a charge of -3 x10 ^-8 C is at x=3 cm. The potential energy of this arrangement, relative to the potential energy for infinite separation is :

-4.9 x 10^-4 J

A particle with a charge of 5x10^-6 C and a mass of 20 b moves uniformly with a speed of 7 m/s in a circular orbit around a stationary particle with a charge of -5x10^-6 C. The radius of the orbit is :

.23 M

Two thin spherical shells, one with radius R and the other with radius 2 R, surround an isolated charged point particle. The ration of the number of field lines through the larger sphere o the number through the smaller is:

1

An electron has charge -e and mass m. A proton has charge e and mass 1840m A proton volt is equal to what?

1 eV

Each plate of a capacitor stores a charge of magnitude 1 mC when a 100 V potential difference is applied. The capacitance is :

10 milli Ferads

If 500 J of work are required to carry a charged particle between two points with a potential difference of 20 V, the magnitude of the charge on the particle is :

12.5 C

The electric field at a distance of 10 cm from an isolated point particle with a charge of 2 x 10 ^-9 C is

1800 N/C

A conducting sphere has charge Q and its electric potential is V, if the charge is doubled to 2Q the potential is:

2 V

To charge a 1 F capacitor with 2 C requires a potential difference of :

2 V

A wire contains a steady current of 2 A. The number of electrons that pass a cross section in 2s is:

2.5 times ten to the nineteen

The potential difference between two points is 100 V. If a particle with a charge of 2 C is transported from one of these points to the other, the magnitude of the work done is

200 J

Two particles, one with cahrge 8 x 10^-9 C and the other with charge -2 x 10 ^-9 C, are separated by 4 m. The electric field between them is :

22.5

Two large parallel conducting plates are separated by a distance d, placed in a vacuum, and connected to a source of potential difference V. An oxygen ion, with a charge 2e, starts from rest on the surface of one plate and accelerates to the other. If e denotes the magnitude of electron charge, the final kinetic energy of this ion is:

2eV

Four wires meet at a junction. The first carries 4 a into the junction. The second carries 5 a in out of the junction, the third carries 2 a out of the junction, the fourth carries

3 a into the junction

During a lightning discharge, 30 C of charge move through a potential difference of 1.0 x 10 ^ 8 V in 2.0 x 10 ^-2 s. The energy released by the lightning bolt is:

3.0 x10 ^ 9 J

Two identical conducting spheres A and B carry equal charge. They are separated by a distance much larger than their diameters. A third identical conducting sphere C is uncharged. Sphere C is first touched to A, then to B, and finally removed. As a result, the electrostatic force between A and B, which was originally F, becomes:

3F/8

A wire carries a steady current of 2 A. The charge that passes a cross section in 2s is:

4 C (duh, its multiplication)

An isolated charged point particle produces an electric field with magnitude E at a point 2 m away. At a point 1 m from the particle the magnitude of the field is :

4 E

Eight identical spherical raindrops are each at a potential V. They combine to make one spherical raindrop whose potential is :

4 V

An isolated charged point particle produces an electric field with magnitude E at a point 2 m away from the charge. A point at which the field magnitude is E/4 is:

4 m away from the particle

Two identical charges, 2 m apart, exert forces of magnitude 4 N on each other. The value of either charge is:

4.2 x 10 ^-5 C

A particle with a charge of 5.5 x 10^-8 C is fixed at the origin. A particle with a charge of -2.3 x 10^-8 C is moved away from x - 3.5 cm on the x axis to y = 4.3 on the y axis. The change in potential energy of the two particle system is:

6 x 10 ^-5 J

The potential difference between the ends of a 2 meter stick that is parallel to a uniform electric field is 400 V. The magnitude of the electric field is

800 V/m

A 5 C charge is 10 m from a -2 C charge. The electrostatic force on the positive object is:

9.0x10^8 N toward the negative charge

To make an uncharged object have a negative charge we must:

Add some electrons

A coulomb is the same as:

An ampere x second

Electric field lines :

Are none of the above.... They are representations only????

Two charged point particles are located at two cerices of an equilateral triangle and the electric field is zero at the third vertex. We conclude :

At least one other charged particle is present.

Two charged point particles are located at two vertices of an equilateral triangle and the electric field is zero at the third vertex. We conclude :

At least one other charged particle is present.

Two point particles, with the same charge, are located at two vertices of an equilateral triangle. A third charged particle is palced so the electric field at the third vertex is zero. The third particle must:

Be on the perpendicular bisector of the line joining the first two charges.

A positively charged metal sphere A is brought into contact with an uncharged metal sphere B. As a result:

Both spheres would be positively charged

A farad is the same as :

C/v

The units of capacitance are equivalent :

C^2 / J

The sum of the currents int a junction equals the sum of the currents out of the junction is a consequence of

Conservation of charge

The sum of the emfs and potential differences around a closed loops equals zero is a consequence of

Conservation of energy

A conducting sphere, with radius R, is charged until the magnitude of the electric field just outside the surface is E. The electric potential of the sphere, relative to the potential far away, is :

ER

Two small charged objects attract each other with a force F when separated by a distance d. If the charge on each object is reduced to one fourth of its original value and the distance between them is reduced to d/2 the force becomes:

F/4

Choose the correct statement concerning electric field lines :

Field lines are close together where the field is large. Field lines cannot cross Field lines are far apart where the field is large A charged particle released from rest does not move along a field line

Two particles, X and Y, are 4m apart. X has a charge of 2 Q and Y has a charge of Q. The force of X on Y:

Has the same magnitude as the force of Y on X

Pulling the plates of an isolated charged capacitor farther apart

Increases the potential difference

Charge is distributed uniformly on the surface of a spherical balloon (an insulator) A point particle with charge q is inside. The electrical force on the particle is greatest when :

It is anywhere inside

Charge is distributed on the surface of a spherical conducting shell. A point particle with charge q is inside. If polarization effects are negligible other electrical force on the particle is greatest when :

It is anywhere inside ( the force is zero everywhere )

The units of the electric field are:

J / (C x m)

Two particles A and B have identical charge Q. For a net force of zero to be exerted on a third charged particle it must be placed:

Midway between A and B

UNITS for 1/(4 x pi x epsilon zero)

N x m^2 / C^2

The units of the electric field are??

N/C

A conductor is distinguished from an insulator with the same number of atoms by the number of :

Nearly free electrons

When a hard rubber rod is given a negative charge by rubbing it with wool:

Negative charges are transferred from wool to rod

If E = 0 at a point P then V must be zero at P

No

The potential of a negatively charged conductor must be negative

No

A protoon tends to go from a region of low potential to a region of high potential

Nooooope

A positively charged insulating rod is brought close to an object that is suspended by a string. If the object is attracted toward the rod we can conclude:

Nothing - you can not show that the object is charged or not orrrrrrrr if it is an insulator or conductor

The electric field due to a uniform distribution of charge on a spherical shell is zero:

Only inside the shell

In a certain region of space the electric potential increases uniformly from east to west and does not vary in any other direction. The electric field :

Points east and does not vary with position.

A capacitor C "has a charge Q" ..... the actual charges on its plates are :

Q, -Q

A small object has a charge Q. Charge q is removed from it and placed on a second small object. The two objects are placed 1 m apart. For the force that each object exerts on the other to be a maximum, what should q be?

Q/2

Two conducting spheres are far apart. The smaller sphere carries a total charge Q. The larger sphere has a radius that is twice that of the smaller and is neutral. After the two spheres are connected by a conducting wire, the charges on the smaller and larger spheres, respectively, are :

Q/3 and 2Q/3

To make an uncharged object have a positive:

Remove some electrons

An electron is accelerated from rest through a potential difference V. Its final speed is proportional to :

Square root of V

Two particles have charges of Q and -Q. For a net force of zero to be exerted on a third charge it must be placed :

THERE IS NO PLACE.

A certain physics textbook shows a region of space in which two electric field lines cross each other. We can conclude that :

The author made a mistake. hahaha

If the charge on a parallel plate capacitor is doubled :

The electric field is doubled

The diagram shows the electric field lines in a region of space containing two small charged spheres (Y and Z). Then L

The electric field is not zero anywhere. Except for an infinitely far distance away from the spheres.

An electron volt is :

The energy gained by an electron in moving through a potential difference of 1 Volt

An electric field is most directly related to :

The force acting on a test charge

A positively charged insulating rod is brought close to an object that is suspended by a string. If the object is repelled away from the rod we can conclude:

The object is positively charged

If the plate area of an isolated charged parallel plate capacitor is doubled :

The potential difference is halved

Charge Q is spread uniformly along the circumference of a circle of radius R. A point particle with charge q is placed at the center of this circle. Tee total force exerted on the particle can be calculated by Coulombs law

The result of the calculation is zero.

Experimenter A uses a test charge q and experimenter B uses a test charge -2q to measure an electric field produced by stationary charges. A finds a field that is:

The same in both magnitude and direction as the field found by B

An electron goes from one equipotential surface to another along on of the four paths.....

The work is always the same

A neutral metal ball is suspended by a string. A positively charged insulating rod is placed near the ball, which is observed to be attracted to the rod. This is because:

There is a rearrangement of the electrons in the ball.

Two point particles, with charges of q and x, are placed a distance r apart. The electric field is zero at a point P between the particles on the line segment connecting them. We conclude that:

They must have the same sign but have different magnitudes.

An electrical insulator is a material:

Through which electrons do not flow easily

The work required to carry a particle with a charge of 6 C from a 5 V equipotential surface to a 6 V equipotential surface and back again to the 5 V surface is 0

True

A hollow metal sphere is charged to a potential V. The potential at its center is :

V

Positive charge is distributed uniformly throughout a non-conducting sphere. The highest electric potential occurs :

at the center

The charge on a glass rod that has been rubbed with silk is called positive:

by arbitrary convention

The equipotential surfaces associated with a charged point particle are :

concentric spheres centered at the particle

The capacitance of a parallel plate capacitor with a plate area A and a plate separation d is given by :

eA/2d

In the rutherford model of the hydrogen atom, a proton, (mass M, charge Q) is the nucleus and an electron (mass m, charge q) moves around the proton in a circle of radius r. Let k denote the coulomb force constant. And G the universal gravitational constant. The ratio of the electrostatic force to the gravitational force between electron and proton is:

kQq/GMm

Let k denote 1/(4 x pi x epsilon zero) The magnitude of the electric field at a distance r from an isolated point particle with charge q is:

kq/ r^2

The capacitance of a parallel plate capacitor is :

proportional to the plate area

the capacitance of a parallel plate capacitor can be increased by : decreasing the plate separation

true

If both the plate area and the plate separation of a parallel plate capacitor are doubled, the capacitance is

unchanged