How Do Magnets Affect TV Screens?

[jackster18]

Homework Statement

A strong magnet is placed on the screen of a television set (permanently damaging the tube). Explain the following observations.
a) the picture becomes distorted
b) the screen is completely dark where the field is strongest

Homework Equations

none.

The Attempt at a Solution

Hi. I am in grade 12 physics and this is a research project that I have to do. I have been researching for about two hours but cannot find a website that explains what is really happening in detail (I have to write from 500 - 1000 words). So far I have found out that TV’s shoot electrons across the front of the screen or something...and when you put the magnet in front it changes the direction of the electron. I need a more detailed explanation of why this is occurring, and I also need to find out why the screen is "completely dark where the field is strongest". If anyone can help I would greatly appreciate it. If you can please post websites that I can go to to read about it because I have to source where I find my information, and I’m pretty sure (no offence to anyone that uses these forums) my teacher will say that “physics help and math help forums” is not a reputable source...even though I know it is because I’ve gotten help here many times before on questions and got them correct.

Here’s some websites I found on my own but they don’t explain the phenomenon very well.

http://electronics.howstuffworks.com/tv2.htm
http://answers.yahoo.com/question/index?qid=20080213151223AAOdkWa&show=7
http://answers.yahoo.com/question/index?qid=20080415195637AACwmEb
http://galileo.phys.virginia.edu/classes/106/1995/omp/030195.html
http://www.soundonsound.com/sos/1995_articles/apr95/homestudio2.html?print=yes
http://howthingswork.virginia.edu/television.html
http://www.theharmonychipstory.com/viewart.html?id=479-2
http://electronics.howstuffworks.com/question694.htm
http://www.colorado.edu/physics/2000/tv/merging_color.html

So yea, if you know anything about this and where to find information on it please post the websites on here. Thanks.

 

[JimChampion]

"Completely dark" means no electrons are hitting the screen there. Find out how a magnetic field could make an electron do a U-turn.

 

[jackster18]

i can't find anything on U-turns of electrons in magnetic fields

 

[JimChampion]

You should be able to find something about charged particle trajectories in magnetic fields. For example circling or spiralling trajectories. A U-turn is part of a circle.