1. Unit 3 – Characteristics of Electricity

2. 7.1 Static Charge = Electrical charge that is collected in one place
Positive and Negative Charges
Solid materials are charged due to the movement of electrons
when electrons are gained, the object becomes negative
when electrons are lost, the object becomes positive
Electrons are most often transferred through friction
For ex., when objects rub against each other
See pages

3. 7.1 Insulators and Conductors
Insulators = materials that do not allow charges to move easily
Conductors = materials that allow electrons to travel freely
Only insulators are good at keeping static charge
Charge is measured with a unit called the coulomb (C)
See page 252
(c) McGraw Hill Ryerson 2007

4. 7.1 Generating Static Charge
Van de Graaff generators (VDG) use friction to make large amounts of static charge.
A spinning belt carries a charge picked up from a brush at the end of a tube to another brush at the top where the charge is distributed onto a metal sphere.
See page 253
(c) McGraw Hill Ryerson 2007

5. 7.1 Applications and Dangers
Positives:
electrostatic filters clean air
paint automobiles
hold objects with electrostatic attraction (ex. cling wrap)
See pages
(c) McGraw Hill Ryerson 2007

6. (c) McGraw Hill Ryerson 2007
Negatives: can be dangerous if it builds up & discharges
serious shocks
Explosions
fires
To avoid build-up, objects must be grounded (connected to the Earth so that static charge is discharged).
(c) McGraw Hill Ryerson 2007