Electrical Circuits

Holt: Physics Ch. 20 – 1

Pages 730-735

Electrical Circuits Schematic diagrams – Graphical

representations of an electrical circuit.

Electrical Circuits Standard symbols used to represent

components. (Page 730)

Bulb / Lamp

Wire

Open Switch

Closed Switch

Resistor

Plug

+_

Battery

Electrical Circuits Electrical circuits - Set of electrical

components connected to provide one or more complete paths for movement of charge.

Electrical Circuits

Short circuit – a circuit which contains little or no resistance

Produces heat, can cause fires

Examples:

- 2 terminals of a battery directly connected

- Uninsulated wires come into contact

Dangerous

Electrical Circuits Load – any element or group of elements in

a circuit that dissipates energy EMF – Electromotive force → the energy per

unit charge supplied by a source of electric current

→ A source of electrical energy

→ A “charge pump”

→ Examples are batteries and generators

Electrical Circuits

*There is some internal resistance in a battery which lowers the voltage available to be used

Energy is constantly converted

1. Chemical potential energy is converted to

electrical potential energy

2. Electrical potential energy is changed to

thermal energy, light, mechanical energy

Electrical Circuits

Homework:

1. Read Chapter 20 section 1

2. Page 735 #1-5

3. Read Chapter 20 section 2: Resistors in

series (Pages 736-740)