Physics 2225: Faraday’s Law Purpose Study the induction of electric current according to...
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Physics 2225: Faraday’s Law Purpose • Study the induction of electric current according to Faraday’s Law.
Transcript of Physics 2225: Faraday’s Law Purpose Study the induction of electric current according to...
Physics 2225: Faraday’s Law
Purpose
• Study the induction of electric current according to Faraday’s Law.
Physics 2225: Faraday’s Law
Faraday’s Law
tB
Induced electromotive Force (“voltage”)
Change in the magnetic fluxthrough the loop
Time interval over whichthe flux change occurs.
Physics 2225: Faraday’s Law
Magnetic Flux Through a Loop of Wire
cosABB
Cross sectional areaof the loop
B
Physics 2225: Faraday’s Law
An Example of Induced Voltage
e
B
e
B
090cos, ABinitialBABABfinalB 0cos,
Time it took to rotate coil by 90: Dt
t
BA
ttinitialBfinalBB
average
,,
Physics 2225: Faraday’s Law
Activity 1: Flux Change by Moving Magnet
LED
Plug LED connector into2000 turn detector coil
LED light turns green or red, depending onthe polarity of thevoltage.
Physics 2225: Faraday’s Law
Activity 1: Flux Change by Moving Magnet
Cow magnet
Move cow magnet EXTREMELY QUICKLYin and out of the detector coil.Watch color of LED duringmovement.
Physics 2225: Faraday’s Law
Activity 2: Flux Change Using Function Generator
Function Generator
200 turn field coil: Called “field” coil because it is used to generate a magnetic field by running current through it.
An alternating current (from function generator)creates an alternating magnetic field by thiscoil.
Physics 2225: Faraday’s Law
Activity 2: Flux Change Using Function Generator: Setup
BNC T-piece
Signal generator output
BNC to Banana adapter
“Banana” cables
Ch 1: Monitors signalfrom signal generator(and thus the B-fieldgenerated by thefield coil).
Ch 2: Monitors the voltage induced inthe detector coil.
Now you can compare thesetwo on the two oscilloscopechannels
Don’t use middleconnector
Physics 2225: Faraday’s Law
Activity 3: Replacing Field Coil with Small Coil
Signal generator output
Physics 2225: Faraday’s Law
Activity 4: Flux Change by Moving Magnet, Observed with Oscilloscope
Plug both BNC cable and LED into the detector coil
Similar to Activity 1, but also monitor voltage with Ch. 1 of oscilloscope.
Set timescale to 500ms,vertical scale as needed.
