Deck 8: Static and Current Electricity

Question 1

Which of these scientists pioneered the study of electricity?

A)Isaac Newton
B)Galileo
C)Benjamin Franklin
D)all of the above

Answer 1

C

Question 2

When you remove electrons from a metal cup,the cup becomes

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

Answer 2

B

Question 3

As you comb your hair,electrons are rubbed onto the comb,which becomes

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

Answer 3

A

Question 4

A rubber rod rubbed with fur becomes

A)positively charged.
B)negatively charged.
C)both
D)neither

Question 5

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 of these
D)none of the above

Question 6

The electric charge of all electrons

A)vary from atom to atom.
B)vary from ion to ion.
C)are identical.

Question 7

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 8

The fundamental force underlying all chemical reactions is

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

Question 9

Which force binds atoms together to form molecules?

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

Question 10

A positive ion has a deficiency of

A)electrons.
B)neutrons.
C)negative ions.

Question 11

To say that electric charge is conserved is to say that electric charge

A)occurs 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 neither be created nor destroyed.

Question 12

The nucleus of an atom is charged

A)positively.
B)negatively.
C)both of these
D)none of the above

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

Compared to the mass of a proton,the mass of an electron is

A)very much less.
B)identical.
C)greater.

Question 15

When you scuff electrons from a carpet onto your shoes,you become

A)negatively charged.
B)positively charged.
C)polarized.
D)ionized.
E)neutralized.

Question 16

The pair of protons in the nucleus of a helium atom

A)attracts a pair of orbiting electrons.
B)repels orbiting electrons.
C)both of these
D)neither of these

Question 17

If you strip electrons from an atom,the atom becomes a

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

Question 18

Two positively-charged plastic straws near each other tend to

A)attract each other.
B)repel each other.
C)neutralize each other.

Question 19

Which of these has the greatest mass?

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

Question 20

An electron and a proton

A)attract each other.
B)repel each other.
C)attract or repel depending on distance.

Question 21

An electrically polarized object normally has

A)a net charge of zero.
B)displaced charges.
C)both of these
D)none of the above

Question 22

When the distance between two charges is halved,the electric force between the charges

A)quadruples.
B)doubles.
C)is half.
D)is reduced by one-quarter.
E)none of the above

Question 23

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

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

Question 24

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

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

Question 25

A negatively charged rod is brought near a metal can that rests on a wooden table.You touch the opposite side of the can momentarily with your finger.The can then becomes

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

Question 26

The electric force between charges is strongest when the charges are

A)close together.
B)far apart.
C)either of these

Question 27

If electrons were positive and protons were negative,Coulomb's law would be written

A)the same.
B)somewhat differently.
C)very differently.

Question 28

Two charged particles near each other are released.As they move,the force on each particle increases.Therefore,the particles have

A)the same sign.
B)the opposite sign.
C)not enough information

Question 29

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

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

Question 30

To say that an object is electrically polarized is to say

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)it is to some degree magnetic.

Question 31

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

A)negatively.
B)positively.
C)either of these
D)none of the above

Question 32

Two charged particles 1 m apart exert a 1-N force on each other.If the particles are instead 0.5 m apart,the force on each particle will be

A)1.0 N.
B)2.0 N.
C)4.0 N.
D)8.0 N.
E)16.0 N.

Question 33

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

A)one electron.
B)one proton.
C)a specific large number of electrons.

Question 34

A negatively-charged balloon touching a wooden wall

A)pulls positive charge on the wall surface toward it.
B)pushes negative charge in the wall away from it.
C)polarizes molecules in the wall.
D)all of the above
E)none of the above

Question 35

Two charged particles 1 m apart exert a 1-N force on each other.If the magnitude of each charge is doubled,the force on each particle will be

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

Question 36

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

A)the net charge on an object has changed.
B)the net amount of charge on an object has increased.
C)net charge has been created or destroyed.
D)none of the above

Question 37

The electric force between charges depends on the

A)magnitude of electric charges.
B)separation distance between electric charges.
C)both of these
D)none of the above

Question 38

Two charged particles 1 m apart exert a 1-N force on each other.If the particles are instead 0.25-m apart,the force on each particle will be

A)1.0 N.
B)2.0 N.
C)4.0 N.
D)8.0 N.
E)16.0 N.

Question 39

A positive and a negative charge near each other are released.As they move,the force on each particle

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

Question 40

A difference between electric and gravitational forces is that electric forces include

A)separation distance.
B)repulsive interactions.
C)the inverse-square law.
D)infinite range.
E)none of the above

Question 41

Two charged particles near each other are released.As the particles move,the velocity of each increases.Therefore,the particles have

A)the same sign.
B)the opposite sign.
C)not enough information

Question 42

The electric field lines between a pair of equal and opposite charges are

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

Question 43

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

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

Question 44

Electric potential is measured in units of

A)volts.
B)joules.
C)amperes.
D)watts.
E)any or all of these

Question 45

Normally a balloon charged to several thousand volts has a relatively small amount of

A)charge.
B)energy.
C)both of these
D)none of the above

Question 46

The electric field around an isolated electron has a certain strength at a 1-cm distance 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 47

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 48

Electric potential 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 49

If you do 10 J of work to push 1 coulomb of charge into an electric field,its voltage with respect to its starting position is

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

Question 50

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 51

Every proton in the universe is surrounded by its own

A)electric field.
B)gravitational field.
C)both of these
D)none of the above

Question 52

A charged balloon illustrates that something can have a great amount of

A)potential energy and a low voltage.
B)voltage and a small potential energy.
C)both voltage and potential energy.
D)none of the above

Question 53

When a battery does 24 J of work on 10 C of charge,the voltage it supplies is

A)2.4 V.
B)4.2 V.
C)24 V.
D)240 V.
E)none of the above

Question 54

Electric charge distributes itself on conducting surfaces

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

Question 55

The electric field between oppositely-charged parallel plates is

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

Question 56

It takes 10 J of work to push a charge into an electric field.Relative to its starting position it has gained a potential energy of

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

Question 57

Food cooked in a microwave oven depends on electrical

A)conduction.
B)charge polarization.
C)resistance changes.
D)field strength.
E)all of the above

Question 58

Electric field lines about a point charge extend

A)outward when the charge is negative.
B)outward when the charge is positive.
C)in circles.

Question 59

It takes 10 J of work to push a charge initially at rest into an electric field.If the charge is then released,it flies back to its initial position with a kinetic energy of

A)zero.
B)5 J.
C)10 J.
D)more than 10 J.
E)need more information.

Question 60

The direction of an electric field is defined as the direction of force on

A)a positively-charged particle.
B)a negatively-charged particle.
C)any charged particle.

Question 61

Just as water flows from high to low pressure,electric charge flows from

A)high to low voltage.
B)high charge concentration to low charge concentration.
C)high resistance to low resistance.
D)all of the above
E)none of the above

Question 62

An ampere is a unit of electric

A)pressure.
B)current.
C)resistance.
D)all of the above
E)none of the above

Question 63

The flow of electrons in an electric circuit move by

A)bumping other electrons.
B)colliding with molecules.
C)interacting with an established electric field.
D)none of the above

Question 64

Which is more dangerous,touching a faulty 120-V light fixture,or a Van de Graaff generator charged to 100,000 V?

A)light fixture
B)generator
C)both equally

Question 65

Voltage is most similar to

A)pressure.
B)current.
C)resistance.
D)all of the above
E)none of the above

Question 66

Just as a sustained flow of water in a hydraulic circuit needs a pump,the flow of charge in an electric circuit needs

A)current.
B)voltage.
C)resistance.

Question 67

Electric charge will flow in an electric circuit when

A)electric resistance is low.
B)a potential difference exists.
C)the circuit is grounded.
D)electric devices in the circuit are not defective.

Question 68

The amount of energy given to each coulomb of charge flowing through a 12-V battery is

A)12 J.
B)12 A.
C)12 V.
D)all of the above
E)none of the above

Question 69

Electrons flow in a wire when there is

A)an imbalance of charges in the wire.
B)a potential difference across its ends.
C)a difference in potential energy across its ends.
D)none of the above

Question 70

A suitable electric pump in an electric circuit is a

A)chemical battery.
B)generator.
C)both of these
D)neither of these

Question 71

The different outcomes in touching a faulty 120-V light fixture and a high-voltage Van de Graaff generator have to do with differences in

A)sustainability of charge flow.
B)duration of charge flow.
C)amount of energy transferred.
D)all of the above
E)none of the above

Question 72

The photo on page 193 shows Lillian's hair standing out when her hand is on a charged Van de Graaff generator,which illustrates

A)strands of hair become charged and repel one another.
B)a high voltage is communicated to strands of hair.
C)strands of hair orient themselves in an electric field.
D)the effect of electrons and protons deposited on her hair.

Question 73

The electric current in a copper wire is normally composed of

A)electrons.
B)protons.
C)ions.
D)all of the above

Question 74

The purpose of a voltage source is to provide an electrical

A)energy sink.
B)field.
C)pressure.

Question 75

A sustained electric current can be achieved with a

A)generator.
B)battery.
C)both
D)none of the above

Question 76

Lillian safely touches a 100,000-volt Van de Graaff generator.Although the voltage is high,the relatively small amount of charge means a relatively small amount of

A)energy transfer.
B)electric field.
C)polarization.
D)conduction.

Question 77

The flow of charge in a circuit depends on

A)adequate resistance.
B)a potential difference.
C)adequate chemical action.
D)all of the above

Question 78

When we think of electric potential difference,we are thinking about

A)current.
B)voltage.
C)resistance.

Question 79

A term for electric pressure is

A)current.
B)voltage.
C)electric resistance.

Question 80

A sustained flow of electric charge requires

A)a potential difference.
B)a resistance.
C)an electric field.
D)electric polarization.