electric fields

Question 1

what is electrostatics

Answer 1

study of electricity at rest (static)

Question 2

what does it mean when an object is neutral

Answer 2

contain positive and negative charges, but in equal numbers

Question 3

when is an object electrically charged

Answer 3

when there is a little bit more of one type of charge than the other on the object

Question 4

since protons dont move,how do charges become pos/neg

Answer 4

positive charges result from shortage of electrons;negative charges result from excess of electrons

Question 5

what is charge measured in

Answer 5

coulombs C
physical quanity q

Question 6

proton

Answer 6

p+
positively charged sub atomic particle
1.6 X 10^-19 C
heavy
found in nucleus - DONT MOVE

Question 7

how are electrons transfered

Answer 7

through friction

Question 8

atom

Answer 8

the smallest particle of a chemical element that can exist.

Question 9

insulators

Answer 9

materials that do not allow electrons to move through them because the electrons are bound to the atoms within the material

Question 10

conductors

Answer 10

Materials that allow charges (electrons) to move relatively freely through them. due to their structure of positive metal cations which are fixed in position and surrounded by a sea of delocalised electrons.

Question 11

polarisation

Answer 11

attraction between uncharged (neutral) and charged objects

Question 12

how does an electrostatic force come about

Answer 12

2 charges interacting

Question 13

what does the size/intensity of force depend on

Answer 13

size of charge (bigger the charge,greater the force)
distance between charges (smaller the distance,greater the charge)

Question 14

polar molecules

Answer 14

molecules that have already been polarised( have a more positive/negative side
STILL NEUTRAL

Question 15

how does polarisation work (4)

Answer 15

charged object exert a force on neutral object
can attract bound electrons to move
molecules in neutral object shift
resulting in more pos/neg side (OBJECT IS STILL NEUTRAL)

Question 16

what does the principle of conservation of charge imply

Answer 16

if charged body in closed system has shortage of electrons, there must be another body/bodies in that system with excess of electrons

Question 17

net charge of system formula

Answer 17

Qnet = Q1 + Q2

Question 18

what happens when 2 charged bodies (identical in size,insulated) are brought into contact
state the formula

Answer 18

movement of electrons between bodies, after separation they will carry same charge

Qnew=Q1 + Q2 / 2

Question 19

Coulombs Law

Answer 19

Two point charges in free space or air exert forces on each other. The force is directly proportional to the product of the charges and inversely proportional to the square of the distance between the charges

don’t include signs in calculations

Question 20

coulombs law eq

Answer 20

F = kq1q2/ r^2

F= force between charges (Newton-N)
q1q2 = charges (Coulombs - C) (no neg signs)
k= Coulombs constant (9 X 10^9)
r = distance between charges (metres m)

Question 21

Quantisation of charge
formula

Answer 21

Q = nqe

Q= charge (C)
n= number of electrons
qe= charge on 1 electron (1.6 X 10^-19 C - constant)

Question 22

qe/charge of 1 electron

Answer 22

1.6 X 10^-19

Question 23

Coulombs constant

Answer 23

k
9 X 10^9

Question 24

describe the relationships within coulombs law

Answer 24

force between 2 charges is directly proportional to product of charges

force between 2 charges is inversely proportional to the square of distance between charges

Question 25

how would you make F bigger, within the equation of coulombs Law

Answer 25

increase q
decrease r

Question 26

alpha particles

Answer 26

2 X 1.6 X 10^-19 C

Question 27

how to calculate magnitude of force

Answer 27

F= kq1q2/r^2 = Fnew

Fnew/F = ___ times bigga

Question 28

explain vander graaf generator

Answer 28

When a charged conductor is placed in contact with the inside of a hollow conductor, all of the charge on the charged conductor is transferred to the hollow conductor.

Question 29

charge of a proton

Answer 29

1.6 X 10^-19

Question 30

calculating new charge after contact

Answer 30

Qnew=(Q1+Q2)/2
charge = sum in charges/number of objects

Question 31

force unit

Answer 31

Newtons N

Question 32

when 2 insulated charges make contact

Answer 32

total charge spread evenly over objects

Question 33

when 2 insulted charges make contact then separate

Answer 33

charge is halved

Question 34

calculating magnitude of force

Answer 34

Fnew = force formula

Fnew/Fog= ______ times greater

Question 35

how to charge by friction

Answer 35

2 substances rub together
transfer of electrons between them
more positive loses electrons - positively charged
more negative gains electrons - negatively charged

Question 36

electron

Answer 36

e-
-1.6 x 10^-19 C
negatively charged subatomic particle
float around nucleus
involved in charging

Question 37

charge of an electron

Answer 37

-1.6 x 10^-19 C

Question 38

how do like charges behave

Answer 38

repel

Question 39

how do unlike charges behave

Answer 39

attract

Question 40

what does coulombs law tell us

Answer 40

relationship between force, distance and charge

Question 41

electrostatic force

Answer 41

force exerted by static charges on each other

Question 42

what happens if a person insulted from the ground touches the van der graaf

Answer 42

each strand of his hair acquires a net positive charge and is repelled by all the others

Question 43

law of conservation of charge

Answer 43

the net charge of an isolated system remains constant during any physical process