Ejs Open Source Charge Particle in Magnetic Field B Java Applet in 3D
reference:
http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=1800.msg7327#msg7327  Created by prof Hwang Modified by Ahmed
http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=1450msg5484;topicseen#msg5484 Created by prof Hwang

Charge In B-Field
This 3D Ejs Charge particle In B-Field model allows the user to simulate a moving charged particle in two identical uniform magnetic fields separated by a zero magnetic field gap. A charge moving in a magnetic field experiences a magnetic force given by the Lorenz force law
[center] $\vec{F}=\vec{v}\times\vec{B}*q$ = v*B*q*sin(theta) [/center]
where theta specifies the angle between the velocity vector v and the magnetic field B. In this simulation, the velocity and B-field are perpendicular (theta = 90 degrees) and the force is maximum and perpendicular to both v and B as predicted by $\vec{v}\times\vec{B}$. You can adjust the magnitude of the magnetic field B, the mass m and charge q of the charged particles. The slider at the top controls the width of the field free region (it is a percentage of half the window width). The magnetic field is assumed to be uniform $Bz\hat{z}$ inside the magnet region. and the field is zero when outside the boundary.
You can change the location and velocity of the charged particle with mouse drag and drop or with sliders.
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Enjoy!

/htdocs/ntnujava/ejsuser/14019/users/sgeducation/lookang/chargeinNS_pkg/chargeinNS.propertiesFull screen applet or Problem viewing java?Add http://www.phy.ntnu.edu.tw/ to exception site list
1 When $Bz\hat{z}$ is positive and the charge particle is completely inside the $Bz\hat{z}$ field region, which way do positively charged particle circle (clockwise or counter-clockwise as view from the top looking down).  Use the Fleming left hand (thumb Force, second finger B field and middle finger current i ) or right-hand cross product rule $\vec{F}=\vec{v}\times\vec{B}*q$ to determine if the field points into or out of the screen?