The Flow of Electricity

Objectives:

    1.    Give examples of voltage sources that can maintain a potential difference in a circuit..

    2.    Distinguish between AC and DC.

    3.    Describe the structure and uses of dry cells and wet cells.

Resources:

    http://www.sasked.gov.sk.ca/docs/physics/u3b33phy.html

Notes:

Key Terms:

    voltage source    alternating current    direct current    dry cell    wet cell    thermocouple

Review:

Electric current

Resistance:

Voltage

Ohmís Law

 

Everybody knows that in order for a electrical device to work it needs a power source with enough energy to power the device.  More exactly there needs to be enough potential difference (voltage) in the source to power the device.  One type of voltage source is the electrochemical cell.

Electrochemical Cell:

        Provides a steady electric current from chemical energy.

        3 types

 

Dry Cell:

(naio.kcc.hawaii.edu/chemistry/ everyday_battery_fig1.gif)

The dry cell consists of a zinc can, electrolyte paste, and a carbon rod in the center.

 Wet Cell:

Also called a voltaic cell and is another type of electrochemical cell.

  Consists of an electrolyte solution, a zinc rod, and a copper rod,

   

 Thermocouple:

Is a device that changes heat energy into electrical energy.

Consists of a heat source,         a copper wire,              an iron wire

and a cold source.

 

 

   

 

 

 

 

 

 

Current direction:

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