ELECTRICAL CIRCUITS. What is an electric current? Electric Current - a flow of electrons from the...

ELECTRICAL CIRCUITS

What is an electric current?

• Electric Current - a flow of electrons from the (+) terminal to the (-) terminal of a cell/battery through wires and components

+-

Open and Closed Circuits• Open circuit = switch is open =

no current is flowing = bulb does not light

• Closed circuit = switch is closed = current is flowing = bulb lights up

Circuit Diagram

Cell/Battery

Switch

BulbWires

Resistor in a bulb

Resistor

Circuit Diagram

Types of Circuits

• Series Circuits – current takes only one path and is the same at all the points

Series Circuits• If one bulb blows out, it breaks

the circuit and all the bulbs go out

• If you add more cells/batteries to a series circuit, the bulbs burn brighter

Types of Circuits

• Parallel Circuits – current takes more than one path and is NOT the same at all the points

Parallel Circuits• If one bulb blows out, there is

still another complete circuit for the bulb to stay lit

Conductors and Insulators• Conductors – objects in which

electrical current easily passes through such as metals

• Insulators – objects that resist the flow of electrical current such as plastic, wood, paper, and rubber

Conductor or Insulator?

Conductor

Open or Closed?

Closed

Brighter or Dimmer?

Dimmer

Series or Parallel?

Series

Brighter or Dimmer?

Brighter

Series or Parallel?

Parallel

Open or Closed?

Closed

Series or Parallel?

Series

Series or Parallel?

Parallel

B

A - Resistor

B - Switch

C - Bulb

D – Wire

E - Cell/Battery

A – Parallel

B – Series