electromagnetic induction & alternating current resources: grob: basic electronics textbook:...

Electromagnetic Electromagnetic Induction & Induction & Alternating Alternating

CurrentCurrentResources:Resources:

Grob: Basic Electronics Textbook: Chapters 15&16Grob: Basic Electronics Textbook: Chapters 15&16

http://www.sayedsaad.com/fundmental/3_Basic%20AChttp://www.sayedsaad.com/fundmental/3_Basic%20AC%20Generation.htm%20Generation.htm

http://www.coolmagnetman.com/magindex.htmhttp://www.coolmagnetman.com/magindex.htmhttp://micro.magnet.fsu.edu/electromag/java/index.htmlhttp://micro.magnet.fsu.edu/electromag/java/index.htmlhttp://www.regentsprep.org/Regents/physics/phys03/http://www.regentsprep.org/Regents/physics/phys03/dinduction/default.htmdinduction/default.htm

Michael FaradayMichael Faraday While Orsted discovered a relationship While Orsted discovered a relationship

between magnetism and electricity, Faraday between magnetism and electricity, Faraday discovered the principle of discovered the principle of electromagnetism: that electricity can be electromagnetism: that electricity can be created using magnetism.created using magnetism.

Faraday presenting to the Royal Society

Faraday’s ExperimentsFaraday’s Experiments

http://micro.magnet.fsu.edu/http://micro.magnet.fsu.edu/electromag/java/index.htmlelectromag/java/index.html Show two of Faraday’s experimentsShow two of Faraday’s experiments

Left-Hand: 3 Finger RuleLeft-Hand: 3 Finger Rule

The direction that induced current flows The direction that induced current flows depends upon the direction the flux lines cut depends upon the direction the flux lines cut across the conductoracross the conductor

This direction can be determined by using This direction can be determined by using the 3-finger rule.the 3-finger rule. Pointing finger points fromPointing finger points from

N to S pole.N to S pole. Thumb points in the direction Thumb points in the direction

in which the conductor moves.in which the conductor moves. Middle finger indicates Middle finger indicates

the direction of electron flow.the direction of electron flow.

Alternating CurrentAlternating Current

http://micro.magnet.fsu.edu/http://micro.magnet.fsu.edu/electromag/java/index.htmlelectromag/java/index.html

How it works!How it works!

Alternating Current cont.Alternating Current cont.

AC vs DC (war of currents)AC vs DC (war of currents)Alternating CurrentAlternating Current Nikola Tesla Nikola Tesla

(Westinghouse)(Westinghouse)

Can be generated Can be generated easilyeasily

Can be sent long Can be sent long distances with little distances with little loss in powerloss in power

Does not require Does not require batteriesbatteries

Can be changed into Can be changed into DC easily when neededDC easily when needed

Few generating Few generating stationsstations

Direct CurrentDirect Current Thomas EdisonThomas Edison Can be generated Can be generated

easilyeasily Difficult to send long Difficult to send long

distancesdistances Most devices need Most devices need

DCDC Sometimes requires Sometimes requires

the need for batteriesthe need for batteries Many generating Many generating

substations substations (less than mile)(less than mile)

Sine WaveSine Wave

Volts/Div= ______________ Sec / Div = ______________

Period (Time) = __________ Frequency= ____________Peak V = ________ P-P Voltage = _________ RMS V= _________