### Author Topic: Faraday's law of induction (magnet moving in/out of solenoid)  (Read 33518 times)

#### Fu-Kwun Hwang

• Hero Member
• Posts: 3062
##### Faraday's law of induction (magnet moving in/out of solenoid)
« on: June 07, 2008, 07:08:19 pm »
Faraday's law of induction: The induced electromotive force or EMF in any closed circuit is equal to the time rate of change of the magnetic flux through the circuit.
-*-

Full screen applet or Problem viewing java?Add http://www.phy.ntnu.edu.tw/ to exception site list
• Please feel free to post your ideas about how to use the simulation for better teaching and learning.
• Post questions to be asked to help students to think, to explore.
• Upload worksheets as attached files to share with more users.
Let's work together. We can help more users understand physics conceptually and enjoy the fun of learning physics!

#### Rare

• Newbie
• Posts: 12
• no secretcode:ntnujava/log:1254222188
##### Re: Faraday's law of induction (magnet moving in/out of solenoid)
« Reply #1 on: October 04, 2009, 05:42:26 pm »
Can this simulations used to illustrate the phenomena of electromagnetic induction{( infer from appropriate experiments on electromagnetic induction:
(i) that a changing magnetic flux can induce an e.m.f. in a circuit, (ii) that the direction of the induced e.m.f. opposes the change producing it, (iii)the factors affecting the magnitude of the induced e.m.f.)} ? Thanks a lot

#### Fu-Kwun Hwang

• Hero Member
• Posts: 3062
##### Re: Faraday's law of induction (magnet moving in/out of solenoid)
« Reply #2 on: October 04, 2009, 06:01:13 pm »
Yes. The induced voltage \$epsilon=-frac{d Psi_B}{dt}=-frac{d }{dt}int vec{B}cdot dvec{a}\$
And the current I flow through the meter is proportional to the voltage.
It was designed to illustrate the Faraday's law.

#### lookang

• Hero Member
• Posts: 1772
• http://weelookang.blogspot.com
##### Re: Faraday's law of induction (magnet moving in/out of solenoid)
« Reply #3 on: September 24, 2010, 01:45:22 pm »

Oh, there is a small issue with the Ejs applet at the top post. The slider magnet position xm = _______
on drag without release but still holding on to the slider but not moving, the deflection should be zero. the current codes shows a bug still shows the deflection due to the earlier motion even though motion v = 0.
do you notice it too?
i try to fix the bug sometime beginning of this year before was not successful.

to check the issue, we can also check this applet by Phet, a good example of Faraday's law of induction TAB choose PickUpCoil
« Last Edit: September 24, 2010, 01:54:20 pm by lookang »

#### Fu-Kwun Hwang

• Hero Member
• Posts: 3062
##### Re: Faraday's law of induction (magnet moving in/out of solenoid)
« Reply #4 on: September 24, 2010, 05:46:20 pm »
Thank you for the bug report. It was due to slider taking control (when you drag it without release) and the plottingPanel was paused (unless you release the mouse again).

The problem can be solved if the  default slider was replaced with home made slider inside the plottingPanel.
I will try to fixed it when I have more free time.