Series and Parallel Circuits Circuits Can either be

Series and Parallel Circuits

Circuits ¡Can either be series or parallel.

Series ¡Current only takes one path for electrons ¡Current flows through every part of the circuit

Lights in a Series

Adding Resistors to Series: l. Current in the circuit will go DOWN (lights will dim) l. If you remove a light bulb or one burns out —all go out!

Parallel Circuits ¡More than one path for current to flow

Removing a Light Bulb ¡If you remove a light bulb or one burns out, the others stay on

Lights in Parallel

Voltage in Parallel ¡Voltage is the same across each branch – because each branch is on the same wire

Batteries in Series and Parallel:

¡In series—The voltage is increased. ¡In parallel—No change in voltage; these batteries will last longer!

Simple Circuits ¡ Series circuit l l l ¡ All in a row 1 path for electricity 1 light goes out and the circuit is broken Parallel circuit l l Many paths for electricity 1 light goes out and the others stay on

Would This Work?

The Central Concept: Closed Circuit

circuit diagram Scientists usually draw electric circuits using symbols; Battery (cell) Light (resister) switch wires

Current: continuous flow of electric charges through a material High Current (low voltage) Low Current (high voltage)

Voltage- difference in electric potential between two points (push that causes electrons to move) Low Voltage High Voltage

Resistance: measure of how difficult it is for charges to flow through the objects

One More FINAL Thing: ¡Two Types of Current: ¡DC—Direct Current— produced by solar cells and chemical cells (batteries) ¡Current only flows in one direction.

2 nd type of current: ¡AC—Alternating Current ¡Current flows back and forth (alternates) ¡Found in homes ¡Generators produce AC current

Ohm’s Law _ Simple analogy: Water in a hose Electrons in a copper wire analogous to water in a hose. _ Consider the pressure valve as the applied voltage and the size of the hose as the source of resistance. _ _ The absence of pressure in the hose, or voltage across the wire will result in a system without motion or reaction. _ A small diameter hose will limit the rate at which water will flow, just as a small diameter copper wire limits the flow of electrons.

Ohm’s Law Voltage = Current x Resistance Current (amps)= Voltage Resistance Georg Simon Ohm (1787 -1854)

Ohm’s Law Current (amps)= Voltage Resistance _ the greater the voltage (or pressure) across a resistor, the more the current. _The more the resistance, for the same voltage, the less the current.