Module 1: Electric Charges and Electric Field

Question 1

it describes only the interaction of two point charges

Answer 1

coulomb’s law

Question 2

The magnitude of the electric force between two point charges is directly proportional to the?

Answer 2

product of charges

Question 3

grav. force is always?

Answer 3

attractive

Question 4

In a _________________, the field lines are straight, parallel, and uniformly
spaced

Answer 4

uniform field

Question 5

The product of the charge q and the separation d is the magnitude of a quantity called the

Answer 5

electric dipole moment

Question 6

The ________________________ on a charged object is exerted by the electric field created by other charged objects

Answer 6

electric force

Question 7

when the distance r doubles, the force decreases to _______________ of its initial value

Answer 7

one-quarter

Question 8

The number of protons or electrons in a neutral atom of an element is called the?

Answer 8

atomic number

Question 9

the negatively charged plastic comb causes a slight shifting of charge
within the molecules of the neutral insulator, an effect called?

Answer 9

polarization

Question 10

The SI unit of electric charge is called?

Answer 10

1 coulumb

Question 11

The net force on an electric dipole in a uniform external electric field is?

Answer 11

zero

Question 12

A ______________________ can undergo polarization in the presence of external charge (gains a positive and negative pole)

Answer 12

neutral material

Question 13

these are charged objects that are very small in comparison with the distance r between them

Answer 13

point charges

Question 14

The word “electric” is derived from the Greek word elektron, meaning?

Answer 14

amber

Question 15

Charge easily flows through the material

Answer 15

conductors

Question 16

contain almost all of the atom’s mass in a relatively tiny space

Answer 16

nucleus

Question 17

electrons are used in molecular bonding (covalent bonding), and need a lot of energy to be released from their atoms

Answer 17

insulator

Question 18

he studied the interaction forces of charged particles in detail in 1784

Answer 18

Charles Augustin de Coulomb (1736-1806)

Question 19

Opposite charges exert an __________ force toward each other

Answer 19

attractive

Question 20

Some materials have intermediate properties between conductors and insulators, and are classified as?

Answer 20

semiconductors

Question 21

these obey the principle of superposition of forces

Answer 21

electric forces

Question 22

negatively charged, freely-”orbiting”

Answer 22

electrons

Question 23

charge transfer methods

Answer 23

friction, conduction, and induction

Question 24

We call the location of the charge the?

Answer 24

source point

Question 25

The magnitude of the electric force between two point charges is inversely proportional to the?

Answer 25

square of the distance between them

Question 26

a small charged object

Answer 26

test charge

Question 27

these are atoms with a net positive/negative charge

Answer 27

ions

Question 28

a useful way of interpreting the interaction between charges, is via the concept of

Answer 28

electric fields

Question 29

electrons are only loosely bound to atoms and can need minimal energy to “escape” and move freely

Answer 29

conductor

Question 30

“epsilon-nought” or “epsilon-zero” is also called the?

Answer 30

electric constant

Question 31

it is a line or curve whose tangent at any point is in the direction of the velocity of the fluid at that point

Answer 31

streamloine

Question 32

positive ions

Answer 32

cations

Question 33

This gain or loss of electrons is called?

Answer 33

ionization

Question 34

electric and magnetic forces are caused by (and act on) objects with?

Answer 34

charge

Question 35

But within objects the size of a person or a planet, the net electric force is usually much ___________ than the gravitational force

Answer 35

smaller

Question 36

excess charges in charging by induction are called?

Answer 36

induced charges

Question 37

The algebraic sum of all the electric charges in any closed system is?

Answer 37

constant

Question 38

positively charged; clustered in the nucleus due to strong nuclear interaction

Answer 38

protons

Question 39

this principle states that the two charges exert forces simultaneously on a third charge, the total force acting on that charge is the vector sum of the forces that the two charges would exert individually

Answer 39

principle of superposition of forces

Question 40

these are a schematic representation of the actual electron distribution, a diffuse cloud many times larger than the nucleus

Answer 40

electron shells

Question 41

Like charges may not necessarily be identical in ______________

Answer 41

magnitude

Question 42

whom does Coulomb's Law named after?

Answer 42

Charles-Augustin Coulomb

Question 43

opposite charges may not necessarily be opposite in ______________

Answer 43

magnitude

Question 44

A ________________ creates an electric field in the space around it

Answer 44

charged object

Question 45

The protons and neutrons are held within stable atomic nuclei by an attractive interaction, called the

Answer 45

strong nuclear force

Question 46

it is a pair of point charges with equal magnitude and opposite sign (a positive charge q and a negative charge -q) separated by a distance d

Answer 46

electric dipole

Question 47

The study of stationary (static) or slow-moving electric charges

Answer 47

electrostatics

Question 48

The electric field due to a symmetrical distribution of charge is most easily calculated at a?

Answer 48

point of symmetry

Question 49

these do not permit the easy movement of charge through them

Answer 49

insulators

Question 50

it is an imaginary line or curve drawn through a region of space so that its tangent at any point is in the direction of the electric field vector at that point

Answer 50

electric field line

Question 51

these permit the easy movement of charge through them

Answer 51

conductors

Question 52

Like charges exert a _____________ force on each other

Answer 52

repulsive

Question 53

Charge doesn’t easily flow the material

Answer 53

insulators

Question 54

Coulomb’s law also obeys the?

Answer 54

principle of superposition of forces

Question 55

net charge is 0 and the object is said to be?

Answer 55

electrically neutral

Question 56

Coulomb’s law obeys?

Answer 56

Newton's 3rd Law of Motion

Question 57

what quantity is vector field

Answer 57

vector quantity

Question 58

negative ions

Answer 58

anions

Question 59

The proton and neutron are combinations of other entities called?

Answer 59

quarks

Question 60

a different technique in which the plastic rod can give another object a charge of opposite sign without losing any of its own charge

Answer 60

charging by induction

Question 61

The ______________________ on a point charge due to two or more other charges is the vector sum of the individual electric forces that each of the other charges exert on it

Answer 61

net electric force

Question 62

it is the interactions between electric charges that are at rest (or nearly so)

Answer 62

electrostatics

Question 63

it is thought to be a universal conservation law

Answer 63

conservation of charge

Question 64

Most of the atom’s “volume” is an empty region containing the “_______” of relatively tiny electrons

Answer 64

orbits

Question 65

these are intermediate in their properties between good conductors and good insulators

Answer 65

semiconductors

Question 66

The _____________________________ of the electron or proton is a natural unit of charge

Answer 66

magnitude of charge

Question 67

mass is always?

Answer 67

positive

Question 68

Charge, like mass, is _____________ in any closed system

Answer 68

conserved

Question 69

they are cross sections of the actual three-dimensional patterns

Answer 69

field maps

Question 70

we call the point P where we are determining the field the

Answer 70

field point

Question 71

Atoms gain charge by losing/gaining electrons through?

Answer 71

ionization

Question 72

The source of electric and magnetic forces is a property of matter known as?

Answer 72

electric charge

Question 73

it states that the total electric field at a point P is the vector sum of the fields at P due to each point charge in the charge distribution.

Answer 73

principle of superposition of electric fields

Question 74

gravity is caused by (and acts on) objects with?

Answer 74

mass

Question 75

One of the four fundamental interactions between matter that we know of in physics

Answer 75

electromagnetism

Question 76

when the distance is halved, the force increases to _______________ its initial value

Answer 76

four times