Science 9Aim: Current Electricity

Agenda1. Science Sizzler (Ashton,

Connor)2. Van de Graff Generator Demo3. Current Electricity4. Bill Nye or Magic School Bus5. Next class

Van de Graff GeneratorsA tool used to study electrical

discharge

What is Energy? Electrical Energy?Energy

= ability to do work

Electrical Energy = energy of charged particles= transferred when electrons travel from

place to place

Static Electricity is not useful in operating electrical

devices…why?

Because charge particles are stationary(build-up &

discharge).

Electrical devices need a constant flow of charged

particles!!

The Steady Flow of Charged Particles is called an electrical current

This flow will continue if:

1) There is an energy source2) There is a complete circuit or

path for the particles to flow through

CURRENT ELECTRICITY

- - - - - - - - - - -

AmperesThe rate at which an electrical current flows is measured in Amperes (A), or “Amps” for short

Some Perspective:- Most home electrical devices have a current of less than 15 A.- A wristwatch uses a current of

only a tiny fraction of ampere- Generating station produces

thousands of amperes

Electrical EnergyThe energy carried by charged

particles

Transporting Current ElectricityNeed to get electricity from its source (ex.

hydro dam) to where it will be used (ex. homes)

Materials that allow for an electrical charge through it easily are called CONDUCTORS

Circuitry

A circuit is a path that controls the flow of electricity.

In most electrical circuits, the path in which the electrons flow is made of solid metal wires…

…but circuits can also include gases, fluids, and other substances.

A

B

C

D

CircuitryCircuits include: A) An Energy Source

= Supplies electrons B) A Conductor

= Material allowing flow of electrons C) A Load

= A device that converts electrical energy to another form of energy (ex. heat or light) D) A Switch (Optional)

= Closes and opens a circuit

Voltage (aka – ‘Potential Difference’)

A measure of how much electrical energy each particle carries

Units = volt (V)

Measuring VoltageVoltmeters Red to Positive Terminal Black to Negative Terminal

SAFELY Working with ElectricityRead Pages 284 -287 & Answer questions 1 – 9 on 287

FOR MARKS!!