Deck 22: Electrostatics

Question 1

A positive ion has more

A)electrons than neutrons.
B)electrons than protons.
C)protons than electrons.
D)protons than neutrons.
E)neutrons than protons.

Answer 1

protons than electrons.

Question 2

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

A)may occur in an infinite variety of quantities.
B)is a whole-number multiple of the charge of one electron.
C)will interact with neighboring electric charges.
D)can be neither created nor destroyed.
E)is sometimes positive.

Answer 2

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

Question 3

To become a negative ion, an atom must

A)lose an electron.
B)gain an electron.
C)lose a proton.
D)gain a proton.

Answer 3

gain an electron.

Question 4

An electron and a proton

A)attract each other.
B)repel each other.
C)neither attract nor repel each other.

Question 5

A fundamental rule of electricity is that

A)like kinds of charges repel.
B)unlike kinds of charges attract.
C)both of these
D)neither of these

Question 6

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

A)single electron.
B)specific large number of electrons.
C)neutron.
D)specific number of neutrons.
E)quark.

Question 7

An electrically charged atom is an

A)ion.
B)isotope.
C)both of these
D)neither of these

Question 8

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

A)electrons that surround the nucleus.
B)neutrons in the nucleus.
C)both electrons and neutrons.
D)none of the above

Question 9

Which of these has the greatest mass?

A)proton
B)electron
C)both of these
D)neither of these

Question 10

The pair of protons in the nucleus of a helium atom

A)attract a pair of orbiting electrons.
B)repel orbiting electrons.
C)both of these
D)neither of these

Question 11

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

A)the total charge on an object has changed.
B)quantity of negative charge on an object exactly balances positive charge.
C)the total quantity of charge on an object has increased.
D)net charge has been created or destroyed.
E)none of the above

Question 12

To become a positive ion, an atom must

A)lose an electron.
B)gain an electron.
C)lose a proton.
D)gain a proton.

Question 13

Which of these does NOT have an electrical charge?

A)proton
B)electron
C)neutron
D)all of the above
E)none of the above

Question 14

The fundamental force underlying all chemical reactions is

A)gravitational.
B)nuclear.
C)centripetal.
D)electrical.
E)none of the above

Question 15

If electrons are stripped from an atom it becomes a

A)positive ion.
B)negative ion.
C)different element.
D)molecule.

Question 16

The force that binds atoms together to form molecules is

A)gravitational.
B)nuclear.
C)electrical.
D)centripetal.
E)none of the above

Question 17

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

A)may occur in an infinite variety of quantities.
B)is a whole number multiple of the charge of one electron.
C)will interact with neighboring electric charges.
D)can be neither created nor destroyed.
E)is sometimes negative.

Question 18

Electrostatics is a branch of electricity that focuses on

A)electrical charge.
B)electrical force.
C)both of these when static.
D)none of the above

Question 19

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

A)electrical charges.
B)electrical forces.
C)electrical interactions.
D)none of the above

Question 20

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

A)mutual repulsion is incomplete.
B)they are attracted by an equal number of protons.
C)they are strongly bonded to their atoms.
D)all of the above
E)none of the above

Question 21

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

A)attract.
B)repel or attract.
C)obey the inverse-square law.
D)act over shorter distances.
E)are weaker.

Question 22

A transistor is an example of a

A)resistor.
B)superconductor.
C)semiconductor.
D)dry cell.
E)transmitter.

Question 23

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

A)F.
B)2 F.
C)F/2.
D)F/4.
E)none of the above

Question 24

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

A)gravitation.
B)electrical.
C)neither of these

Question 25

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

A)F.
B)2 F.
C)F/2.
D)F/4.
E)none of the above

Question 26

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

A)electrons than protons.
B)protons than electrons.
C)energy than an insulator.
D)faster moving molecules.
E)none of the above

Question 27

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

A)half as much.
B)the same.
C)twice as much.
D)four times as much.
E)none of the above

Question 28

The electrical force between electric charges depends only on their

A)magnitude.
B)separation distance.
C)both of these
D)neither of these

Question 29

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

A)F.
B)2 F.
C)F/2.
D)F/4.
E)none of the above

Question 30

Insulating materials are composed of atoms with

A)weak cohesive forces.
B)tightly bound outer electrons.
C)excess protons.
D)vastly more charge than conductors.

Question 31

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

A)negative.
B)smaller.
C)loosely bound.
D)none of the above

Question 32

The electrical force between charges is strongest when the charges are

A)close together.
B)far apart.
C)either of these
D)need more information

Question 33

Superconductors are noted for their

A)high electric resistance.
B)low electric resistance.
C)absence of electric resistance.
D)low cost.
E)bright colors.

Question 34

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

A)1 N.
B)2 N.
C)4 N.
D)8 N.
E)16 N.

Question 35

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

A)0.11 N.
B)0.33 N.
C)0 N.
D)3 N.
E)9 N.

Question 36

Conducting materials are composed of atoms with

A)strong cohesive forces between them.
B)loose outer electrons.
C)excess neutrons compared with protons.
D)vastly more charge than insulators.

Question 37

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

A)1 N.
B)2 N.
C)4 N.
D)8 N.
E)none of the above

Question 38

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

A)is reduced by 1/4.
B)halves.
C)doubles.
D)quadruples.
E)none of the above

Question 39

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

A)F.
B)2 F.
C)F/2.
D)F/4.
E)none of the above

Question 40

A semiconductor can be

A)a conductor.
B)an insulator.
C)both of these
D)neither of these

Question 41

An uncharged pith ball is suspended by a nylon fiber. When a negatively-charged rubber rod is brought near the pith ball, without touching, the ball

A)becomes charged by induction.
B)becomes polarized.
C)is repelled by the rod.
D)is unaffected.
E)none of the above

Question 42

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

A)closer together.
B)farther apart.
C)motionless.

Question 43

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

A)positively charged.
B)negatively charged.
C)partially discharged.
D)completely discharged.
E)none of the above

Question 44

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

A)positively charged.
B)negatively charged.
C)partially discharged.
D)completely discharged.
E)none of the above

Question 45

To say that an object becomes electrically polarized means that

A)it is electrically charged.
B)its charges have been rearranged.
C)its internal electric field is zero.
D)it is only partially conducting.
E)none of the above

Question 46

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

A)friction.
B)contact, which means touching.
C)induction, which means non-touching.
D)all of the above
E)none of the above

Question 47

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

A)negatively charged.
B)positively charged.
C)discharged.

Question 48

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

A)increases.
B)decreases.
C)stays the same.

Question 49

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

A)the same sign.
B)opposite signs.
C)the same mass.
D)the same size.
E)need more information

Question 50

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

A)the same sign.
B)opposite signs.
C)need more information

Question 51

An uncharged pith ball is suspended by a nylon fiber. When a positively-charged rubber rod is brought nearby, the pith ball

A)moves toward the rod.
B)is unaffected.
C)moves away from the rod.
D)none of the above

Question 52

A common naturally-polarized bit of matter is

A)an electron.
B)a hydrogen atom
C)a water molecule.
D)all of the above
E)none of the above

Question 53

A balloon will stick to a wooden wall if the balloon is charged

A)negatively.
B)positively.
C)either of these
D)neither of these

Question 54

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

A)normally huge, but for a brief time.
B)small enough to be safe for a passenger inside.
C)zero.

Question 55

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

A)the same sign.
B)opposite signs.
C)either of these
D)need more information

Question 56

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

A)positively charged.
B)negatively charged.
C)uncharged.

Question 57

Superconductors most often require

A)low operating temperatures.
B)high operating temperatures.
C)magnets.

Question 58

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

A)Coulomb's law.
B)conduction and insulation.
C)charge polarization.
D)voltage.

Question 59

Before a thunder storm, clouds in the sky likely become

A)conducting.
B)polarized.
C)grounded.
D)a field-free region.

Question 60

The primary purpose of a lightning rod is to

A)attract lightning and guide it to the ground.
B)discharge the structure to which it is attached.
C)cancel the electric field within the structure to which it is attached.
D)induce a charge opposite to that of charged clouds overhead.

Question 61

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

A)electron
B)proton
C)both accelerate equally.
D)none of the above

Question 62

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

A)F/q.
B)4F/q.
C)F/(2q).
D)F/(4q).
E)none of the above

Question 63

The operation of a microwave oven makes use of

A)the polar nature of water molecules.
B)flip flopping of polarized molecules.
C)an oscillating electric field.
D)all of the above
E)none of the above

Question 64

Electric charge distributes itself on conducting surfaces

A)with greater concentration on more curved parts.
B)such that the electric field inside is zero.
C)both of the above
D)none of the above

Question 65

Much of the charge on a conducting cube is

A)uniformly spread over its surface.
B)partly beneath the surface.
C)mutually repelled toward its corners.
D)none of the above

Question 66

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

A)F/q.
B)4F/q.
C)F/(2q).
D)F/(4q).
E)none of the above

Question 67

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

A)0.25 V.
B)0.5 V.
C)1 V.
D)2 V.
E)4 V.

Question 68

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

A)less than zero.
B)zero.
C)greater than zero.

Question 69

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

A)less than 10 V.
B)10 V.
C)more then 10 V.
D)none of the above

Question 70

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

A)not obey the inverse-square law.
B)cancel one another.
C)be set in motion until equilibrium is established, on the outside.
D)all of the above
E)none of the above

Question 71

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

A)a neutral test charge.
B)an electron.
C)an atom.
D)a proton.
E)a molecule.

Question 72

Electric shielding within a conductor is a consequence of

A)the balancing of opposing forces.
B)both the attraction and repelling nature of electricity.
C)cancellation of electric field lines.
D)all of the above
E)none of the above

Question 73

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

A)half as much.
B)the same.
C)twice as much.
D)four times as much.
E)none of the above

Question 74

The net charge on a charged capacitor depends on

A)the area of the capacitor plates.
B)the distance between the capacitor plates.
C)the medium between the capacitor plates.
D)all of the above
E)none of the above

Question 75

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

A)steel.
B)iron.
C)aluminum.
D)wood.

Question 76

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

A)20 N/C.
B)30 N/C.
C)60 N/C.
D)120 N/C.
E)240 N/C.

Question 77

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

A)current.
B)resistance.
C)charge.
D)voltage.
E)none of the above

Question 78

The electric field between oppositely-charged parallel plates is

A)uniform.
B)stronger at the ends.
C)composed of field lines in opposite directions.
D)none of the above

Question 79

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

A)directed from positive to negative.
B)more concentrated closer to the charges.
C)vectors, with patterns that stem from the inverse-square law.
D)all of the above
E)none of the above

Question 80

Every isolated proton in the universe is surrounded by its own

A)electric field.
B)gravitational field.
C)both of these
D)neither of these