Chapter 12- Electrostatic Phenomena

Two metal balls, A and B, of the same size and material touch Prior to touching, A had a charge of --6 μC while B had a charge of 4 μC. After touching, the charge on B is _____.

-1 μC

Two metal balls, A and B, of the same size and material touch. Prior to touching, A had a charge of 6 μC while B was uncharged. After touching, the charge on B is _____

3 μC

A positive charge feels a force of 5 N due to another negative charge. The negative charge must feel a force of _____ in the opposite direction according to Newton's third law.

5 N

Two metal balls, A and B, of the same size and material touch. Prior to touching, A had a charge of 6 μC while B had a charge of 4 μC. After touching, the charge on B is _____.

5 μC

A charge of --1 C is approximately how many electrons?

A million-trillion

You have three pith balls labeled A, B, and C. Each has been given an electrostatic charge, but you do not know what kind each has. When you bring A and B close together, you find they repel and when you bring B and C together you find they also repel. Which statement is true?

A, B, and C all have the same type of charge.

Which of the following terms apply to an atom that has the negative part of its charge separated from the positive part? (Check all that apply.)

Dipole Polarized

Consider three electric fields A, B, and C. The electric field lines are the closest to each other in field A, while they are the farthest from each other in field C. Which of the following statements is true of these electric fields?

Electric field A is the strongest.

Which of the following statements are true about an electric field? (Check all that apply.)

Electric field can exist in a vacuum. We can talk about an electric field even if there is no charge at that point.

Match the electric phenomenon (in the left column) with the presence or absence of a charge (in the right column).

Electrostatic force--------Requires a charge to be present Electric field------A charge is not present.

Match the force (in the left column) with the possible directions that the force can take (in the right column).

Gravitational force-------The force is always attractive. Electrostatic force------The force may be attractive or repulsive.

Match the charge (in the left column) with the direction of the electric field lines from the charge (in the right column).

Positive charge-----All electric field lines point away from the charge. Negative charge-----All electric field lines point toward the charge.

We define an electric field as the force a test charge q0 would feel at a given point. What are the characteristics of the test charge? (Check all that apply.)

Positively charged The test charge is a point charge.

Match the nature of two charges (in the left column) with the behavior exhibited (in the right column).

Same charges-----------Repel each other Opposite charges--------Attract each other

Match the objects (in the left column) with the most relevant force law (in the right column).

The Earth and the moon---Newton's law of universal gravitation Atomic particles----Coulomb's law

Select all that apply What determines how much work is required to move a charge?

The change in voltage between the two points The amount of charge being moved

On a dry day, you comb your hair and can tell from the crackling sound that an electric charge has been placed on your comb. Which one of the following is of this?

The comb will exert an electrostatic force on another charged object.

Select all that apply Which of the following statements are true of the leaves of a simple electroscope? (Check all that apply.)

The leaves spread apart when charged. The leaves hang straight down when uncharged.

Select all that apply Which of the following can be determined when the charge on a particle and the electric field are known?

The magnitude of the electric force The direction of the electric force

Select all that apply In which of the following situations would the atom be a dipole?

The negative part of the atom is displaced to the right of the positive center of the atom. The negative part of the atom is displaced to the left of the positive center of the atom.

When can we treat charged objects as point charges?

The objects are small compared to the distance separating them

Select all that apply You have set up two pith balls so that they have different types of charge, and you have put an unknown charge on a rod. If you test the type of charge on the rod, what conclusions will you find?

The rod carries one of the two types of charge already on the pith balls. The rod will attract one pith ball and repel the other.

Select all that apply Which of the following are advantages of electroscopes over pith balls?

The stability of the foil leaves The stationary testing point of the metal ball

Select all that apply Having two parallel metal plates of equal but opposite charge is _____. (Check all that apply.)

a way of making a uniform electric field a method for storing charge called a capacitor

Two objects with opposite charges will____________ each other.

attract

The electric field lines from a positive charge always point _____ the charge.

away from

The electrostatic force is conservative. This means we _____. (Check all that apply.)

can recover any work done by the electrostatic force can convert the electrostatic potential energy to kinetic energy without loss of energy can use the principle of the conservation of energy

Two plates of equal but opposite charge placed parallel to each other such that they give rise to a uniform electric field in the region between them is called a

capacitor

Two plates of equal but opposite charge placed parallel to each other such that they give rise to a uniform electric field in the region between them is called a_________

capacitor

An insulator does not normally allow________ to flow through it.

charge

Select all that apply The electrostatic force between a charged rod and a charged ball depends on the _____.

charge on the rod distance between the ball and the rod charge on the ball

A material that allows charge to flow readily through it is called a(n) _____.

conductor

The charge on objects is measured in units called________ . Just one of these units is an immense amount of charge.

coulombs

When the center of a positive charge is separated by a slight distance from the center of a negative charge in an atom of neutrally charged object, the atom is called an electric________

dipole

According to Coulomb's law, the electrostatic force will be a quarter of what it was if we__________ the distance between the charges. Listen to the complete question

double

Electrostatic force is caused by__________ charges.

electric

In a uniform electric field, the change in voltage is proportional to the _____. (Check all that apply.)

electric field distance

A negatively charged object has a surplus of_______________

electrons

A positively charged object has a deficit of____________

electrons

Electric__________ lines depict the direction of the electrostatic force on a point charge when it is brought into that region of space.

field

The electrostatic force acts at a distance even through empty space. Thus, we say that a charge in an empty space gives rise to an electric_______________ , which changes the space due to the presence of the charge.

field

Coulomb's law gives the electrostatic______between two charges.

force

The electric field at a given point is the electrostatic______per unit positive charge.

force

Placing a charged insulator near a metal ball forces the charges to separate (positive from negative). Using your finger to touch the opposite side of the metal ball from the charged insulator will drain off those charges and leave the metal ball charged. This is called charging by

induction

A material that does not ordinarily allow charge to flow readily through it is called a(n) ______.

insulator

The units for electric potential are______per unit charge.

joules

The units for voltage are_______ per unit charge.

joules

If the charged objects are much smaller than the distance between them, we call them_____charges

point

To construct electric field diagrams, we imagine placing a ________charge at all locations and drawing an arrow with the direction and magnitude of the electric force on the test charge at each point.

positive

The change in the electrostatic potential energy per unit positive charge is the change in the electric_____

potential

The spring force and gravitational force are both conservative. The electrostatic force is also conservative, meaning we can define an electrostatic_____energy.

potential

A material that is not a good conductor but also not a good insulator is called a(n)

semiconductor

The denser a the electric field lines are in a region, the________ the electric field is in that region.

stronger

A positive charge feels a force of 10 N to the right due to another negative charge. The negative charge must feel a force of 10 N to the left according to Newton's_________law

third

In a uniform electric field, the change in the_______ is equal to the electric field times the distance the charge travels.

voltage

The presence of a charge in an area changes the region because any other charge in the region _____

will feel a force

When an insulating ball is approached by a charged rod, the pith ball becomes an electric dipole in the presence of the charged rod. At this point, the overall charge on the pith ball will be

zero

Select all that apply The work done on any object is the force times the distance. The work done on a charge, q0, by a constant electric field, E, moving at constant velocity, v0, over a distance, d, in a time, t, Identify the equation for the increase in potential energy of the charge .

∆PE = qEd q0

Identify the equation for the increase in potential energy of the charge.

∆PE=qEd