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 Author Topic: Charge in a uniform magnetic field in 3D  (Read 8134 times) 0 Members and 1 Guest are viewing this topic. Click to toggle author information(expand message area).
ahmedelshfie
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 « Embed this message on: June 10, 2010, 12:35:30 am »

This following applet is Charge in a uniform magnetic field in 3D
Created by prof Hwang Modified by Ahmed
Original project Charge in a uniform magnetic field in 3D

$\vec{F}=q\vec{v}\times\vec{B}$.
The following show a charged particle trapped bwtween two uniform field.
You can use sliders to change the width and the separation between two sets of magnet.
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.

Embed a running copy of this simulation

Embed a running copy link(show simulation in a popuped window)
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• 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!
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lookang
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 « Embed this message Reply #1 on: October 04, 2010, 12:17:40 pm »

46% of students surveyed got this question wrong, that means false.
A constant magnetic field never changes the speed magnitude of velocity of a charged particle which moves in it. (Bagno & Eylon, 1997)

the analysis are:
a. Recitation of formula: field applies force, and force causes acceleration according to Newton’s second law of motion 40% of 46% who got it wrong
b. Blind substitution into formula 37
c. No reason 23

Using this applet, you can see the velocity does not change.
A constant magnetic field never changes the speed magnitude of velocity of a charged particle which moves in it.

Bagno, E., & Eylon, B.-S. (1997). From problem solving to a knowledge structure: An example from the domain of electromagnetism. American Journal of Physics, 65(, 726-736. doi: 10.1119/1.18642
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lookang
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 « Embed this message Reply #2 on: October 04, 2010, 12:23:30 pm »

hmmmm, i think i need to customize it for exploring and visualization of

The velocity of a charged particle moving in a magnetic field is always perpendicular to the direction of the field.
37% think it is true, but the answer is false. it could be a supposition of uniform velocity and circular motion, thus there is an angle =! 90o between v and B, much like a helix path

a. Recitation of formula: v, B and F are always perpendicular according to left hand or right screw law 81
b. No reason 19
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"Reflect, review and renew constantly." ...Wisdom