CHAPTER 18 - PHYSICS - ELECTRIC CHARGE

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When a charge is established on an object, the change exists because the electrons have moved to or from the object. true false

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It is impossible to detect types of charges with an electroscope. true false

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J. J. Thomson found that electric charge is continuous, i.e., that any amount of charge was possible. true false

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J. J. Thomson found the magnitude of an electron's charge. true false

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J.J. Thomson found that electric charge is continuous, i.e., that any amount of charge was possible. true false

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Like charges repel each other. true false

resinous electricks

Materials that acted like amber resinous electricks vitreous electricks

vitreous electricks

Materials that acted like glass resinous electricks vitreous electricks

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Materials that hold their electrons firmly are called conductors. true false

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Materials that hold their electrons loosely are called conductors. true false

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Metals are generally poor conductors since they do not allow freedom of movement of their electrons. true false

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Millikan discovered the magnitude of the fundamental charge. true false

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Millikan found the magnitude of an electron's charge. true false

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The electroscope is a device for detecting electrostatic charges. true false

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The electroscope is good for measuring electric force. true false

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The electroscope works best as a detector of charge. true false

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The force of repulsion between two like charges is due to electrostatic force. true false

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The force of repulsion between two like charges is due to static electricity. true false

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The law of charges states that like charges attract and unlike charges repel one another. true false

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The law of charges states that like charges repel and unlike charges attract each other. true false

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The magnitude of the fundamental charge is the same for positive and negative charges. true false

Robert Millikan.

The scientist who discovered the charge of an electron was J. J. Thomson. Robert Millikan. Benjamin Franklin. William Gilbert.

J. J. Thomson

The scientist who discovered the electron was J. J. Thomson. Robert Millikan. Benjamin Franklin. William Gilbert.

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The two ways by which a body may be charged are by contact and by induction. true false

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Electrons had not yet been discovered in Franklin's time. true false

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According to Coulomb's law, doubling the distance between two charged bodies will halve the force between them. true false

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All electrical charges on atoms, molecules, and ions are multiples of the fundamental charge. true false

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An electrick is any substance that can easily conduct electricity. true false

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An electroscope's main purpose is to detect charges true false

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An object is charged because electrons have traveled either to or from the object. true fe

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An object is charged because protons have traveled either to or from the object. true false

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Charles Du Fay's findings that there are two kinds of charge agree with our current knowledge. true false

an electrical fluid.

Benjamin Franklin and Charles DuFay assumed electricity to be a flow of negative charge. an electrical fluid. a solid or liquid. discontinuous. tiny particles that surround the atom.

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Benjamin Franklin believed in the existence of electrons as the determiners of charge. true false

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Benjamin Franklin called resinous electrification negative. true false

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Benjamin Franklin called resinous electrification positive. true false

insulators

Both vitreous and resinous electricks are types of conductors. semi-conductors. insulators. semi-insulators.

torsion balance

Coulomb experimented with electrostatic forces using a(n) _____. oil-drop apparatus electroscope charged rod and dust particles torsion balance

Newton's law of universal gravitation

Coulomb's law is similar to which of the following laws? the first law of thermodynamics Newton's law of universal gravitation Newton's third law the law of the conservation of angular momentum

true

Coulomb's law states that the force between two charges is directly proportional to the product of the charges and inversely proportional to the square of the distance between them. true false

inversely proportional to the square of the distance between the bodies.

Coulomb's law states that the force of attraction between two charged bodies is directly proportional to the distances between the bodies. directly proportional to the square of the distances between the bodies. inversely proportional to the square of the distance between the bodies. inversely proportional to the product of the charges of the two bodies.

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Doubling the distance between two charged objects will cut the force between them to one-fourth. true false

true

Electric charge is not continuous. true false

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Electricity is the flow of electrons. true false

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Electroscopes can determine the presence and sign of a charge. true false

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Electrostatic force depends on the magnitudes of the distance and the charges. true false

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Franklin and Du Fay both thought that the cause of electrification had something to do with fluids. true false

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Franklin said that resinous electricks had a deficiency of negative fluid. true false

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Franklin said that resinous electricks had a deficiency of positive fluid. true false

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Franklin's idea about one fluid is close to the modern theory of electron flow for solids. true false

They were insulators.

Gilbert's electricks had what type of electrical properties? They were conductors. They were insulators. They were semiconductors. They had no special electrical properties.

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Glass is a good conductor of electricity. true false

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Glass is a good insulator of electricity. true false

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Glass, amber, rubber, and Lucite are electricks true false

two

How many electroscopes does it take to demonstrate conduction? one two three four

two

How many electroscopes does it take to test conduction? one two three four

2

How many types of electricks are there? 1 2 3 4

false

If 2 objects repel each other, you know that they are both negative charges. true false

false

If the distance between two charged particles doubles, the force exerted between them will be halved. true false

false

If two charges exert an electrostatic force on each other and one charge is twice the other, then the larger charge will exert twice the force of the smaller charge and the smaller charge will exert half the force of the larger. true false

true

In early times, scientists thought that charged objects contained one of two types of fluids. true false

true

Induction of an electrostatic charge requires only the presence of a charged object not actual contact, to establish a charge in another object. true false

true

No charges have been found that are fractions of the charge of an electron. true false

true

Nonmetals are generally poor conductors since they do not allow freedom of movement of their electrons true false

true

On humid days, charged objects lose their charges more quickly because the presence of water vapor makes the air more conducive. true false

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One esu of charge on each of two bodies 1 cm apart results in a force of 1 dyne.

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Solids with many free (mobile) electrons are called conductors. Insulators contain few free electrons (their electrons are tightly held). true false

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The SI unit of charge is the esu. true false

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The charge of an electron, of which all charges are multiples, is called the fundamental charge. true false

established the fact that every electron carries a charge of the same magnitude.

Robert Millikan's oil drop experiment established the fact that every electron carries a charge of the same magnitude. did not actually measure the charge of an individual electron. always resulted in drops which were positively charged. yielded results showing that the charge was not always in discrete values.

a negatively charged rod is brought near the electrode. a positively charged rod is brought near the electrode. a negatively charged rod touches the electrode. a positively charged rod touches the electrode. a second negatively charged rod is brought near the electrode. a second positively charged rod is brought near the electrode.

Select all that apply. The leaves of an electroscope move from their original positions and separate if a negatively charged rod is brought near the electrode. a positively charged rod is brought near the electrode a negatively charged rod touches the electrode. a positively charged rod touches the electrode. a second negatively charged rod is brought near the electrode. a second positively charged rod is brought near the electrode. a second negatively charged rod touches the electrode (after a negatively charged rod had previously touched the electrode and been removed). a second positively charged rod touches the electrode (after a positively charged rod had previously touched the electrode and been removed).

Metals are conductors. They contain many free electrons. Electrons are loosely held.

Select all that apply. Which of the following is true of conductors? Metals are conductors. Glass is a conductor. Rubber is a conductor. They contain many free electrons. They contain few free electrons. Electrons are tightly held. Electrons are loosely held.

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Semiconductors are materials that hold their electrons in a way that allows a flow of electricity only under certain conditions. true false

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Solids that have many free electrons are called insulators. true false

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Thomson disproved the continuous charge concept when he showed that all matter contained discrete units of charge. true false

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Thomson showed that all matter contains separate and discrete charges called electrons. true false

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Uncharged electroscope can be used to indicate the presence, sign, and magnitude of electrostatic charge on an object. true false

contact induction

What are the 2 ways to charge an object?

The leaves remain separated for an extended period of time.

What happens when you touch an electrified piece of amber to a neutral electroscope? The leaves separate momentarily, then fall back to their original position. The leaves remain separated for an extended period of time. The leaves do not respond to the electrified piece of amber. The leaves which were already separated separate even farther.

coulomb

What is the SI unit for charge? dyne electrostatic unit coulomb newton

an insulator

What must the stopper of an electroscope be made of? an insulator a conductor a semiconductor it does not matter

oil

What substance was used in the measurement of the fundamental charge? water oil acetone perfume

oil

What substance was used to measure the fundamental charge? water oil acetone perfume

true

When charge is added to an object by way of an electrical ground, it is most efficiently charged using the method of induction. true false

separate

When you bring a charged rod near the electrode of the electroscope, the leaves attract each other. separate. separate and then quickly move back together. do not move.

the earth

Which makes the best electrical ground for a large charge? a person the earth a tire an electroscope

iron

Which of the following is a conductor? glass ceramic plastic iron

There is no electrical charge that has been found to be a fraction of the charge of an electron.

Which of the following is true? Protons are a fraction of the charge of an electron. Neutrons are a fraction of the charge of an electron. All electrical charges are a fraction of the charge of an electron. There is no electrical charge that has been found to be a fraction of the charge of an electron.

an electrical ground

Which of the following is unaffected when electrons are added? an oil drop an electrostatic torsion balance an electroscope an electrical ground

porcelain

Which of the following substances is classified as an electrical insulator? porcelain tin copper mercury

William Gilbert

Who was/were among the first to experiment extensively on electrification? the Greeks Charles Du Fay William Gilbert Benjamin Franklin

Robert Millikan

Whose work disproved the idea that charged objects contained electric fluids by showing that charged objects possessed particles with a certain charge? William Gilbert Charles Du Fay J. J. Thomson Robert Millikan

because it eliminates static charge on the can

Why must you place a gas can on the ground before you add gasoline to it? because it's more stable because it's easier to fuel because it eliminates static charge on the can because you can more easily view the level in the can

conductors

__ contain many free electrons conductors insulators

insulators

___ contain few free electrons conductors insulators

resinous electricks

___ contained resinous fluids resinous electricks vitreous electricks