6th Grade Ch 2 Sec 2 Electric CurrentPresentation Transcript
Ch. 2 Sec. 2 Electric Current
continuous flow of electric charges thru. a material
Representing an Electric Current
complete, unbroken path thru. which electric charges can flow
Simple Circuits activity
potential energy per unit of electrical charge
2 factors that affect flow of current voltage (potential difference) resistance
material through which a charge can flow easily
material thru which electric currents move freely
electrons are only loosely bound to their atoms
eg. copper, silver
material through which a charge can not flow easily
charges are not able to move freely
electrons are bound tightly to their atoms
eg. plastic, wood
Conductors and Insulators [00:59] Conductors and Insulators Online Activity
Voltage (potential difference)
Difference in electrical potential between 2 places
Causes current to flow thru. electric circuit
unit = volt
Voltage in a circuit is similar to the difference in potential energy on a roller coaster.
POTENTIAL DIFFERENCE Just as water flows downhill, electrons flow from places of higher potential to places of lower potential. The difference in electrical potential between two places is called potential difference.
WHAT IS VOLTAGE? Voltage is potential difference measured by a ______________ ? VOLTMETER The unit of measure in potential difference is called the volt. For that reason, potential difference may be called voltage.
ELECTRON FLOW Electrons will flow as long as there is a potential difference or voltage between two parts of a circuit.
WHAT CAUSES CURRENT TO FLOW?
Voltage causes current to flow through an
electric circuit. The flow of electrons through a
material is called ___________?
creates potential difference
eg. battery & generator
increase in voltage causes greater flow of electric current
has 2 terminals
measure of how difficult it is for charges to flow thru. a material
unit = ohm
factors that determine resistance of a wire material from which wire is made length of wire diameter of wire temp. of wire
Charges flow through the wire, not the bird, because the wire offers less resistance.
Time to review
BBC - Schools Science Clips - Circuits and conductors BBC- Schools Science Clips-Changing Circuits http://www.learningcircuits.co.uk/
What happens when an electric current is produced?
a continuous flow of charges travel through a material
Contrast electric current and static electricity.
An electric current is a continuous flow of charge. In static electricity, charges build up but do not flow.
Explain why electric current cannot exist if an electric circuit is broken.
charges cannot flow because the path is not complete
Define conductor and insulator.
conductor = material is a material through which charges can flow through easily
insulator = material through which charges cannot flow through easily
List materials that make good conductors. List materials that make good conductors.
good conductors = silver, copper, aluminum and iron
good insulators = rubber, sand, plastic and wood.
Create a concept map using the following terms:
Electric current resistance voltage ohms volts amps