current electricity

potential difference (voltage)

-In a battery, a series of chemical reactions occur in which electrons are TRANSFERRED from one terminal to another. What is BETWEEN the poles?

-where the charge begins to where it ends

electromotive force or (EMF)

-The MAXIUMUM potential difference a power source can have

-isn't actually a force, simply the amount of energy per charge

-(J/C or V)

push and pull

When a wire connects the terminals of a battery or generators, the voltage will __ and ___ electrons through a conductor.

negative, positive

Electrons in the wire are PUSHED by the ____ terminal and PULLED by the ____ terminal through the wire.

voltage

electrical PRESSURE that pushes and pulls charges

1. A source of energy

2. A closed path

3. A device which uses the energy

All electric circuits have three main parts:

fluids

Electricity can be symbolic of ____

2

A circuit works on _ IMPORTANT PRINCIPLES

electric current

The amount of CHARGE that flows PER SECOND

-the rate at which charge FLOWS through a surface

conventional current

-The current is in the same direction as the flow of positive charge

-the flow of current from the positive terminal of a power source to the negative terminal

direct and alternating

2 types of Current

Direct Current

-current flows in one direction

-Example: Battery

Alternating Current

-current reverses direction many times per second.

-This suggests that AC devices turn OFF and ON.

-Example: Wall outlet (progress energy)

Ohm’s Law

The current in a circuit is:

• directly proportional to voltage

• inversely proportional to the resistance

I=V/R or V=IR

voltage vs current graph

resistence = slope

Electrical Resistance (R)

the ability of a material to resist the flow of charge (ohms)

-Changes electrical energy into thermal energy and light

-Ex: lightbulb filament

1) Voltage provided by source

2) Electric resistance of the conductor

The amount of charge that flows through a circuit depends on two things:

Resistor

A circuit device that is designed specifically to limit current flow.

any

___ device can be modeled with a resistor.

larger, smaller

The ____ the resistor/resistance the ___ the current that flows through them

lost

Voltage (Potential Difference) is ____ through resistors.

wire

The medium through which charges flow.

long

thin

hot

what creates more resistance:

length

cross-sectional area

temperature

copper

aluminum

material that creates less resistance:

material that creates more resistance:

Kilowatt-Hour (kWh)

The amount of energy consumed in 1 hour at a rate of 1 kW

Power

“rate” in formula (W)

energy —> heat and light

energy conversion in an incandescent light bulb

energy —> heat + kinetic

energy conversion in a clothes dryer

energy —> sound + light

energy conversion in a digital clock radio

A= C/s

unit of electric charge in terms of MKS units

in series

How must an ammeter be connected in a circuit to correctly read the current?

in parallel

how must a voltmeter be connected to a resistor in order to read the potential difference across it?

battery

-a device that converts chemical energy into electrical energy

-a source of electrical potential, essentially a voltage, that pushes electrons through a circuit

electric circuit

a closed path that allows electric current to flow continuously

conservation of charge

the net charge of an isolated system will always remain constant