# Electricity

## circuits

A circuit is a closed loop that electrons can travel in. Every electrical appliance in your home, whether it's battery operated or you plug it in, is a circuit. There can not be a break in a circuit because the electrons need to flow through the circuit in order for it to function.

## Electrons

• flow is determined by the battery
• flow is always from negative to positive
• electron loss=object is positively charged
• electron gain=object is negatively charged
• electrons that are bound loosely are conductors (metals and glass)
• electrons that are bound tightly are insulators (plastic, wood, and RUBBER)
• opposite charges attract and negative charges rebel

## Bulbs

• are resistors because they resist current flow
• more bulbs=decrease in current and bulb brightness
• contact points (CP's) allow electrical current to flow
• have 2 CP's and each CP must touch another CP of another device

## Series Circuits

• single current paths
• current is always the same throughout the circuit and is measured in Amps
• resistance total is all resistors combined
• resistors represent a given amount of resistance in a circuit and DO NOT have to be the same value (bulbs)
• resistance is the hindrance to the flow of the charge measured in Ohms
(measure of "how hard" it is to "push" through a circuit element).

## Ohms Law

Formula: V=IR

(V = volts; I = current/Amps; R = resistance/Ohms)

## Our Circuit

• simple circuit
• lever, 2 alligator clips, 1 resistor (bulb), and a battery

Fake scenario using Ohms Law for our circuit:

Zach is using his handy-dandy straightener to straighten Keith's hair for picture day. The straightener draws a current of 2.26 Amps on a 5.87 V outlet, how much resistance would the straightener draw?