ELECTRICITY AND MAGNETISM

Electrostatics

The study of stationary electric charges

Electrodynamics

The study of electric charges in motion

Electrific Ground

a reservoir of electric charges

ELECTRIFICATION

► is the process of losing and accepting electric charges

► the act of electrifying or the state of being charged with electricity

1. FRICTION

2. CONTACT

3. INDUCTION

THREE WAYS TO ACHIEVE ELECTRIFICATION

FRICTION

Transfer of electrons from one object to another by means of rubbing (e.g. combing of hair, walking)

CONTACT

Transfer of electrons from one object that is already negatively charged object (excessive electrons) to a positively charged (lacking/needs electrons)

INDUCTION

Electrons move to one part of an object because it is an electric field of another object

Electrostatic Charge

► The smallest unit of electric charge is the electron.

coulomb (C)

The fundamental unit of electric charge

1 C

6.24 × 10^18 electron charges

Atoms

► Have neutrons, protons, and electrons

Protons

are positively charged

Electrons

are negatively charged

Electrons

Are located on the outer edges of atoms…they can be moved.

negative charge

A concentration of electrons in an atom creates a net

positively charged

If electrons are stripped away, the atom becomes

Static Electricity

What is this electrical potential called?

Static Electricity

► The build up of an electric charge on the surface of an object.

► The charge builds up but does not flow.

potential energy

Static electricity is _ _. It does not move. It is stored

Static Discharge

Occurs when there is a loss of static electricity

1. Friction

2. Conduction

3. Induction

Static Discharge occurs when there is a loss of static electricity due to three possible things

Friction

rubbing

Conduction

direct contact

Induction

through an electrical field (not direct contact)

Electric current

Electricity that moves

Electric current

The flow of electrons from one place to another.

kinetic energy

electric current consists of

With circuits

How can we control currents?

Circuit

is a path for the flow of electrons. We use wires.

1. Direct Current (DC)

2. Alternating Current (AC)

There are 2 types of currents

Direct Current (DC)

Where electrons flow in the same direction in a wire

Alternating Current (AC)

electrons flow in different directions in a wire

1. Series Circuit

2. Parallel Circuit

There are 2 types of circuits

Series Circuit

The components are lined up along one path. If the circuit is broken, all components turn off.

Parallel Circuit

there are several branching paths to the components. If the circuit is broken at any one branch, only the components on that branch will turn off.

Series Circuit

► RT = R1 + R2 + R3

► IT = I1 = I2 = I3

► VT = V1 + V2 + V3

Parallel Circuit

► 1/RT = 1/R1 + 1/R2 + 1/R3

► IT = I1 + I2 + I3

► VT = V1 = V2 = V3

Conductors

material through which electric current flows easily

►Metal
►Water

Insulators

materials through which electric current cannot move.

►Styrofoam

►Plastic

►Rubber

►Paper

Semiconductor

a material that under some conditions behave as an insulator and in other conditions behaves as a conductor

Semiconductors

► Silicon (Si)

► germanium (Ge)

Superconductors

the property of some materials to exhibit no resistance below a critical temperature (Tc).

Superconductors

► Niobium

► Titanium

Resistance

The opposition to the flow of an electric current, producing heat

Good conductors

have low resistance

ohms

Resistance is measured in

1. Material of wire

2. Thickness

3. Length

4. Temperature

What Influences Resistance

Material of wire

aluminum and copper have low resistance

Thickness

the thicker the wire the lower the resistance

Length

shorter wire has lower resistance

Temperature

lower temperature has lower resistance

Voltage

The measure of energy given to the charge flowing in a circuit

True

The greater the voltage, the greater the force or “pressure” that drives the charge through the circuit

Amps

measure how much water comes out of a hose

Volts

measure how hard the water comes out of a hose

V = IR

Ohm’s Law Formula