# NTNUJAVA Virtual Physics LaboratoryEnjoy the fun of physics with simulations! Backup site http://enjoy.phy.ntnu.edu.tw/ntnujava/

## Easy Java Simulations (2001- ) => electromagnetism => Topic started by: ahmedelshfie on April 12, 2010, 02:17:41 am

 Title: A loop rotating in a magnetic field (How electric power generator works! Post by: ahmedelshfie on April 12, 2010, 02:17:41 am This applet created by Prof HwangModified by my self I add tow bars for (sc) and (time) Original project:A loop rotating in a magnetic field (How electric power generator works!) (http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=915msg4942;topicseen#msg4942) Title: Re: A loop rotating in a magnetic field (How electric power generator works! Post by: ahmedelshfie on April 21, 2010, 02:42:23 am When a loop rotating in a uniform magnetic field.The magnetic flux is changing which will induce electric field along the loop (produce voltage).If the loop is rotating with constant angular velocity \omega . (The angle is \omega t)The magnetic flux in the loop will be $\Psi =\int \vec{B}\cdot d\vec{A}= B A cos(\omega t)$So the induced emf $= -\frac {d\Psi}{dt}=B A \omega sin(\omega t)$The following simulation show how it works dynamically. Title: Re: A loop rotating in a magnetic field (How electric power generator works! Post by: Fu-Kwun Hwang on April 21, 2010, 10:06:44 am You need to add TeX equation between $to be displayed as equation.I have added dollar sign for the above posted message for you! Title: Re: A loop rotating in a magnetic field (How electric power generator works! Post by: ahmedelshfie on April 21, 2010, 12:21:11 pm Yes prof,, i had the text information and equations from topic http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=912.0So i think I'm make wrong right ??? Title: Re: A loop rotating in a magnetic field (How electric power generator works! Post by: Fu-Kwun Hwang on April 21, 2010, 04:50:40 pm You need to add dollar sign for those equations.Otherwise, those equation would not be convert to image.The following is what you have copied.Code:This simulation shows a current loop in uniform magnetic field.The black arrows show the force due to magnetic field on the loop.\vec{F}= q \vec{v} \times \vec{B} or \vec{F}= I \int d\vec{\ell} \times \vec{B}The magnetic field in in the +Z direction if Bz>0.Then ,torque for the loop is calculated from definition \vec{\tau}=\vec{r}\times\vec{F}Because the current flow in the same counter-clockwise direction.The force on the loop change sign during each helf cycle.If we current reverse direction during each helf cycle, the following device can turn into a motor.A voltage source is needed in the loop to drive the current. Title: Re: A loop rotating in a magnetic field (How electric power generator works! Post by: ahmedelshfie on April 21, 2010, 10:51:46 pm I understand prof so when i would typing any equations i add$ between equationsFor convert to picture right Title: Re: A loop rotating in a magnetic field (How electric power generator works! Post by: Fu-Kwun Hwang on April 22, 2010, 02:48:25 pm Yes!  :D Title: Re: A loop rotating in a magnetic field (How electric power generator works! Post by: ahmedelshfie on April 22, 2010, 05:19:06 pm Yes prof  :)