Unit 4: Gravity and Electrostatics

Question 1

A positive charge will (attract/repel) another positive charge

Answer 1

repel

Question 2

A positive charge will (attract/repel) a neutral charge

Answer 2

attract

Question 3

A positive charge will (attract/repel) a negative charge

Answer 3

attract

Question 4

A negative charge will (attract/repel) another negative charge

Answer 4

repel

Question 5

A negative charge will (attract/repel) a neutral charge

Answer 5

attract

Question 6

Which particle can actually move freely between objects?

Answer 6

electrons (e-)

Question 7

Electric Charge

Answer 7

A property of matter / some elementary particles
- it gives rise to particle interactions and electricity

Question 8

Charge that is stationary

Answer 8

electrostatic charge

Question 9

Charge that moves continuously

Answer 9

electric current

Question 10

where are protons+ found in the atom?

Answer 10

the nucleus

Question 11

where are neutrons found in the atom?

Answer 11

the nucleus

Question 12

where are electrons- found in the atom?

Answer 12

They orbit the nucleus and can move freely

Question 13

if an atom is neutral, it has __(magnitude of p+ and e-)

Answer 13

the same number of protons and electrons

Question 14

Objects with excess of electrons are said to be ( positively / negatively) charged

Answer 14

negatively

Question 15

Objects with a deficiency of electrons are said to be ( positively / negatively) charged

Answer 15

positively

Question 16

Like charges _____, unlike charges _____.

Answer 16

repel, attract

Question 17

Conservation of Charge

Answer 17

Charge cannot be created nor destroyed, but it can be transferred.

Question 18

Charge transfer

Answer 18

reflects the desire to minimize the repulsive forces between excess electrons.

Question 19

charges transfer more easily through (insulators/conductors)

Answer 19

conductors

Question 20

Insulators

Answer 20

materials in which electrons do not move freely

Question 21

Insulator examples

Answer 21

-rubber, wool or silk, plastic, glass, foam

Question 22

Conductors

Answer 22

material in which electrons move freely

Question 23

Conductors examples

Answer 23

metal (copper and aluminium)

Question 24

Charging by Friction

Answer 24

Charging through contact like rubbing
- electrons move because they have been heated and rubbed off
- both objects are neutral
-works with both insulators and conductors

Question 25

Charging by Conduction

Answer 25

When a charged object touches a charged or neutral object
- works with both insulators and conductors

Question 26

Polarization

Answer 26

The rearrangement of atoms or molecules resulting in induced charge on neutral object
-balloon ex, paper punches ex
- only works with insulators

Question 27

Charging by induction

Answer 27

Touch is induced on an object by holding a charged object close by and it is temporary unless you ground it
-only works for conductors

Question 28

Grounding

Answer 28

Provides a pathway for electrons in a sink (take away) or source (give) of electrons
- it is connected to the Earth

Question 29

Ways to charge insulators

Answer 29

friction, conduction, polarization

Question 30

ways to charge conductors

Answer 30

friction, conduction, induction

Question 31

Electrostatic Force (Fe)

Answer 31

The force that results when two charged objects, near one another, experience acceleration towards or away from each other

Question 32

Coulomb’s Law of Electrostatic Force

Answer 32

Fe= Kcq1q2/r2

Question 33

Kc

Answer 33

Coulomb’s constant
8.99 x 10^9 Nm^2/c^2

Question 34

Electric Field

Answer 34

A force field that surrounds an electric charge or group of charges

Question 35

What is E?

Answer 35

Electric Field Strength
the magnitude of the electric field

Question 36

Source Charge (Q)

Answer 36

Alters original space around it producing the field
- field exists because of the source charge
- it’s the charge at the center of the field

Question 37

Test Charges (q0)

Answer 37

Interact with the field at the location and that it is where you see the force
- usually positive
- small and magnitude compared to the source so that it doesn’t alter the field much
- q0 experiences the field and experience it at different points

Question 38

What is the direction of E?

Answer 38

the direction of the Fe on a test charge

Question 39

Uniform Electric Field (UEF)

Answer 39

A field that has the same value and direction at all points

Question 40

Electric Potential Energy (PEelec)

Answer 40

Potential energy associated with the charge due to its position in an electric field

Question 41

Electric Potential (V)

Answer 41

The work that must be performed against electric forces to move a charge from a reference point to the point in question divided by the charge
-energy per charge

Question 42

Electric Potential Difference (^V)

Answer 42

The works that must be performed to move a charge between two points divided by the charge
- the change in electric potential
-voltage