Electricity - grade 9

the continuous flow of electricity in a closed pathway

build up of electric charge on an object because it is not given a path to escape

rubbing together two materials causes electrons to transfer

1 object positive, 1 object negative

they are both neutral

a list of materials arrange in order according to their tendency to gain electrons

• like charges repel

• opposite charges attract

• 1 charged and 1 neutral object attract

friction inside the nozzle causes paint to be negative and the object being painted is either neutral or positively charged so they attract each other

clothes rub together inside the dryer and stick together (called static cling), dryer sheets prevent this by absorbing the negative charge

• 2 objects have different charges

• objects make contact

• electrons transfer until they have the same net charge

an object that allows electrons to flow easily

materials that hold onto their electrons

distilled water does not have any minerals in it, which is what allows normal water to be a conductor

transferring extra charge (+/-) to an infinite reservoir so the object can be neutral

• grounding can cause an object to loose or gain electrons depending on the situation

• it does not matter how many electrons are given to the reservoir because it’ll be spread over a big area

a large neutral object

humans, the earth

a metal ball that will move away/towards an object to indicate the presence of a charge without touching it

an apparatus with metal leaves that will either repel or attract to indicate that a charge is present without touching the object

• 1 neutral, 1 charged object

• charged object goes near neutral object to induce a temporary charge separation

  • a permanent charge can be created via grounding

• water droplets rub against each other inside of clouds and become charged

  • negative drops collect at the bottom of the cloud

• negative drops repel electrons on the earths surface

  • causes a temporary charge separation on the earths surface making the surface positively charged

• excess electrons in the clouds take the path of least resistance to get to the earths surface

  • this creates a permanent negative charge on the earths surface

if an object with a net charge of -3 and an object with a +1 net charge touches, what will be the new net charge?

how can you make an object with a net charge of -4 neutral?

if a negative rod is put near a neutral metal leaf electroscope what will happen?

if you were to ground a negative metal leaf electroscope what will happen?

energy created by water moving a turbine

pro: safe for the environment

con: costly to build dam

a load gets energy directly from the source

a load gets energy from a generating station

Social, environmental, and economic effects

pro: creates jobs, meets energy demands

con: contributing to global warming, stopping this method would cause people to loose jobs

pro: a renewable source of energy if properly managed

con: if incorrectly managed it will have the same effect as fossil fuels

pro: creates jobs and lots of energy

con: produces radioactive waste

pro: renewable

con: hard to harness

pro: easy to harness

con: expensive to set up solar panels

pro: creates jobs, wind is found everywhere

con: hard to find spot with consistent high winds

source, load, conductor

one pathway for electricity to flow

multiple pathways for electricity to flow

this causes damage to the circuit and could start a fire, this happens when there isn’t a load to drop off energy to in a circuit

thin piece of metal that breaks when current exceeds safe rate. This prevents short circuiting

pressure given to current to push it along the circuit

the force opposing the flow of electrons

thickness of wire

length of wire

temperature

material

mathematical representation of the relationship between voltage, current, and resistance

V=IxR

R=V/I

I=V/R

Vt= v1 + v2

It= I1 = I2

Rt= R1 + R2

Vt= V1 = V2

It= I1 + I2

1/Rt= 1/R1 + 1/R2