Electrical Circuits

Electrical Circuit Closed path through which charge can flow A Circuit needs: 1.Source of energy (voltage) 2.Conductive path for charge to flow 3.Source of resistance (device to do work)

Batteries Provide the energy (voltage) for charge to flow in a circuit –Have (+) and (-) terminals

Dry cell Series of chemical reactions causes electrons to flow and accumulate at the (-) terminal –Used in portable electronics + terminal - terminal

Wet Cell Has 2 connected metal plates submerged in an electrolyte: solution that conducts electricity Ex: Car battery

Circuit Diagrams Use symbols to represent parts of a circuit Shows one or more complete paths that charge can flow

Current flow + - Current always flows from positive (+) to negative (-) battery terminal Battery

Series Circuits Charge has only one path to flow If one device stops working they all stop working! Viewing series circuit

Series Circuits Adding light bulbs to a series circuit increases resistance –CURRENT DECREASES, BULBS BECOME DIMMER

Parallel Circuits Circuit with two or more paths for current to flow If one device stops working the rest continue to work!

Parallel Circuits Viewing Parallel Circuit Homes and buildings are wired in parallel Bulbs shine brighter in parallel than series –All Directly connected to battery

Parallel circuits Current in branch depends on resistance –More current flows through the path of lowest resistance Voltage is same across each branch