Physics HW chapter 22

An electron and a proton

attract each other

A reason for electric shielding inside a conductor is that any free electrons inside would

be set in motion until equilibrium is established, on the outside

Part complete The electrical force between electric charges depends only on their

both of these

Electrostatics is a branch of electricity that focuses on

both of these when static

It is said that electric charge is conserved, which means that electric charge

can be neither created nor destroyed

Electric potential, measured in volts, is the ratio of electric energy to the amount of electric

charge

If you rub an inflated balloon against your hair and place the balloon against the wall it will stick to the wall, illustrating

charge polarization

Two charges separated by one meter exert 1-N forces on each other. If the charges are pulled 3 meters apart, the force on each charge will be

0.11 N

An electron is pushed into an electric field where it acquires a 1-V electrical potential. If two electrons are pushed the same distance into the same electric field, the electrical potential of the two electrons is

1 V

Assume that 10 J of work pushes a charge initially at rest into an electric field. If the charge is then released, it flies back to its starting position with a kinetic energy of

10 J

If 10 J of work is used in pushing 1 C of charge into an electric field, its electric potential relative to its starting position is

10 V

Two charges that are separated by one meter exert 1-N forces on each other. If the charges are pushed together so the separation is 25 centimeters, the force on each charge will be

16 N

The electrical force on a 2-C charge is 60 N. The electric field where the charge is located is

30 N/C

Two charges that are separated by one meter exert 1-N forces on each other. If the magnitude of each charge is doubled, the force on each charge is

4 N

The three pairs of metal same-size spheres have different charges on their surfaces, as indicated. Each pair is brought together, allowed to touch, and then separated.

CAB

Two charged particles attract each other with a force F. If the charges of both particles are doubled, and the distance between them also doubled, then the force of attraction will be

F

Two charged particles repel each other with a force F. If the charge of both particles is tripled and the distance between them is also tripled, then the force will be

F

Two charged particles repel each other with a force F. If the charge of one of the particles is doubled and the distance between them is also doubled, then the force will be

F/2

Imagine a single charge q placed at one corner of a square, and that the electric field at the center of the square is F/q. If two other equal charges are placed at the adjacent corners of the square (leaving the opposite corner "blank"), the electric field at the center of the square is

F/q

The direction of an electric field is the direction of the force exerted on

a proton

Superconductors are noted for their

absence of electric resistance

Between a pair of equal and opposite charges, field lines are

all of the above

Electric shielding within a conductor is a consequence of

all of the above

Electrons can be transferred from one place to another by the process of

all of the above

The pair of protons in the nucleus of a helium atom

attract a pair of orbiting electrons

Electric charge distributes itself on conducting surfaces

both of the above

A fundamental rule of electricity is that

both of these

A semiconductor can be

both of these

Every isolated proton in the universe is surrounded by its own

both of these

Normally a small party balloon charged to several thousand volts will have a relatively small amount of

both of these

The electrical force between charges is strongest when the charges are

close together

An electroscope is charged positively as indicated by foil leaves that stand apart. As a negative charge is brought close to the electroscope, the leaves become

closer together

The primary purpose of a lightning rod is to

discharge the structure to which it is attached

Two charged particles held close to each other are released. As they move, their speeds increase. Therefore, their charges have

either of these

Part complete Two protons attract each other gravitationally and repel each other electrically. The stronger of these two forces is

electrical

The force that binds atoms together to form molecules is

electrical

The fundamental force underlying all chemical reactions is

electrical

Just as "gravity" is the study of a wide range of gravitational interactions, "electricity" is the study of a wide range of

electrical interactions

A proton and an electron are placed in an electric field. Which undergoes the greater acceleration?

electron

In an electrically neutral atom the number of protons in the nucleus is equal to the number of

electrons that surround the nucleus

To become a negative ion, an atom must

gain an electron

A positive charge and a negative charge held a certain distance apart are released. As they move, the force on each particle

increases

An electrically charged atom is an

ion

It is said that electric charge is quantized, which means that the charge on an object

is a whole-number multiple of the charge of one electron

To say that an object becomes electrically polarized means that

its charged have been rearranged

Conducting materials are composed of atoms with

loose outer electrons.

Charge carriers in a metal are electrons rather than protons because electrons are

loosely bound

To become a positive ion, an atom must

lose an electron.

Superconductors most often require

low operating temperatures

Much of the charge on a conducting cube is

mutually repelled toward its corners

A positively-charged rod is held near an aluminum can that rests on a dry wood table. If you momentarily touch the opposite side of the can with your finger, the can becomes

negatively charged

If you comb your hair and the comb becomes positively charged, then your hair becomes

negatively charged

Rub electrons from your hair with a comb and the comb becomes

negatively charged

Part complete To say that electric charge is conserved means that no case has ever been found where

net charge has been created or destroyed

Which of these does NOT have an electrical charge?

neutron

A conductor differs from an insulator in that a conductor has more

none of the above

Imagine a single charge q placed on one corner of a square, and that the electric field at the center of the square is F/q. If additional equal charges are placed on the other three corners, the electric field at the center of the square due to these four equal charges is

none of the above

The electric field around an isolated electron has a certain strength 1 cm from the electron. The electric field strength 2 cm from the electron is

none of the above

Two charged particles repel each other with a force F. If the charge of one of the particles is doubled and the distance between them is halved, then the force will be

none of the above

Two charged particles held a certain distance apart are released. As they move, the force on each particle increases. Therefore, their charges have

opposite signs

If electrons are stripped from an atom it becomes a

positive ion

A negatively-charged rod is held near an aluminum can that rests on a dry wood table. If you momentarily touch the opposite side of the can with your finger, the can becomes

positively charged

Which of these has the greatest mass?

proton

A positive ion has more

protons than electrons

When the distance between two charges is halved, the electrical force between them

quadruples

A main difference between gravitational and electric forces is that electrical forces

repel or attract

A transistor is an example of a

semiconductor

Part complete The unit of electric charge, the coulomb, is the charge on a

specific large number of electrons

Although the energy per coulomb of a high-voltage party balloon is high, the energy transfer that occurs if you touch it is low due to

the relatively small amount of charge

Particle A has twice the charge of nearby particle B. Compared to the force on Particle A, the force on Particle B is

the same

Two charged particles held a certain distance apart are released. As they move, the acceleration of each decreases. Therefore, their charges have

the same sign

The vast numbers of electrons in a coin don't fly off the surface because

they are attracted by an equal number of protons

Insulating materials are composed of atoms with

tightly bound outer electrons

The electric field between oppositely-charged parallel plates is

uniform

During a lightning strike you don't want to be inside a building framed with

wood

The electric field inside an uncharged metal ball is zero. If the ball is negatively charged, the electric field inside the ball is then

zero

When a car is struck by lightning, the resulting electric field inside the car is

zero