Physics #5

Question 1

electrostatics

Answer 1

the study of stationary charges and the forces that are created by and which act upon these charges

Question 2

gravity is ____ an attractive force

Answer 2

always

Question 3

is static charge buildup/static electricity more significant in drier air or humid air?

Answer 3

drier air because the lower humidity makes it easier for charge to become and remain separated

Question 4

what is the charge of an electron or a proton?

Answer 4

1 Coloumb

1.6x10^-19

Question 5

like mass and energy, electric charge is governed by a _______. This law states that charge can neither be created nor destroyed.

Answer 5

law of conservation of charge

Question 6

insulator

Answer 6

will not easily distribute a charge over its surface and will not transfer that charge to another neutral object very well.

Question 7

why are insulators poor conductors?

Answer 7

on a molecular level, the electrons of insulators tend to be closely linked with their respective nuclei.

Question 8

conductor

Answer 8

when given a charge, the charges will distribute approximately evenly upon the surface of the conductor.

Question 9

why are conductors so good at transferring charge?

Answer 9

they are considered as positive nuclei surrounded by a sea of electrons.

Question 10

where do electric field lines point?

Answer 10

toward the negative charge.

Question 11

how do electric fields make their presence known?

Answer 11

by exerting forces on other charges that move into the space of the field.

Question 12

what is small q vs. big Q

Answer 12

Q: source charge
q: test charge

Question 13

Is electric field a vector or scalar quantity?

Answer 13

vector

Question 14

by convention, the direction of the electric field vector is given as the direction that a____ test charge would move in the presence of the source charge

Answer 14

positive

Question 15

what do the electric field lines look like for a neutral point in space?

Answer 15

there are none.

Question 16

does the source charge or the point charge create the electric field?

Answer 16

the source charge

Question 17

what is the sign on potential energy if the charges are like charges?

Answer 17

positive

Question 18

what is the sign on potential energy if the sizes are not like charges

Answer 18

negative

Question 19

what are q1 and q1 in the electrostatic force equation?

Answer 19

magnitude of charges

Question 20

How is electrical potential energy defined?

Answer 20

for a charge at a point in space in an electric field it is the amount of work necessary to bring the charge from infinitely far away to that point.

Question 21

A smaller (more negative) potential energy represents _____ stability

Answer 21

more

Question 22

where do two like charges have the greatest stability?

Answer 22

furthest apart

Question 23

where do two unlike charges have the greatest stability?

Answer 23

closest to each other

Question 24

is electric potential a scalar quantity or vector quantity?

Answer 24

scalar

Question 25

for a collection of charges, the total electric potential at a point in space is ______

Answer 25

the scalar sum of the electric potential due to each charge

Question 26

what is the name for the potential difference between two points in space?

Answer 26

voltage

Question 27

the ____ end of a battery is the high potential end while the _____ end of a battery is the low potential end

Answer 27

plus

minus

Question 28

Positive charges will spontaneously move in the direction that ______ their electric potential (_____ voltage), whereas negative charges will spontaneously move in the direction that______ their electric potential (___ voltage). In both cases, electrical potential energy is ___.

Answer 28

decreases, negative
increases, positive
decreasing

Question 29

the potential difference between any two points on an equipotential line is ____

Answer 29

0

Question 30

in electrostatics, work depends only on the _____ and not the path taken

Answer 30

potential difference

Question 31

how do chemists and physicists indicate dipoles differently?

Answer 31

physicists indicate the dipole in the opposite manner of chemists.

Question 32

in a dipole, we are assuming the charges on either end are ______

Answer 32

equal and opposite.

Question 33

what does torque on a dipole moment do?

Answer 33

it causes the dipole moment to reorient itself so the dipole moment aligns with the electric field.

Question 34

any moving charge creates a _____

Answer 34

magnetic field

Question 35

what is the SI unit for magnetic field strength

Answer 35

tesla (N)(s)/(m)(C)

Question 36

diamagnetic materials

Answer 36

made of atoms with no unpaired electrons and that have no net magnetic field. Slightly repelled by a magnet.

Question 37

paramagnetic materials

Answer 37

unpaired electrons so do have a net magnetic dipole moment but no net magnetic field.

weakly magnetized in the presence of an external magnetic field, aligning the magnetic dipoles of the material with the external field.

Question 38

ferromagnetic materials

Answer 38

unpaired electrons so do have a net magnetic dipole moment but no net magnetic field.

strongly magnetized in the presence of an external magnetic field, aligning the magnetic dipoles of the material with the external field.

Question 39

the sum of electrostatic and magnetic forces is known as the ____ force

Answer 39

Lorentz

Question 40

how to do RHR for current carrying wires

Answer 40

thumb in direction of current and wrap fingers

Question 41

how to do RHR for magnetic force

Answer 41

thumb in direction of velocity
fingers in direction of magnetic field lines
palm is direction of force vector for positive charge
back of hand is direction of force vector for negative charge

Question 42

at the perpendicular bisector of a dipole, the electric potential is 0 because ______

Answer 42

electric potentials are additive.