Concepts

Magnetic force on charges

Overview

A permanent magnet can magnetize parts of an old CRT television, distorting the image and colours due to the magnetic force on the electrons. A degaussing coil restores the TV to normal working order.

Details

Equipment

• [1] CRT television with VCR and remote, all on a cart with a power bar
  
• [1] Degaussing coil
  
• [1] Permanent magnet
  

Classroom Assembly

1. Plug in the power bar.
2. Plug the degaussing coil into the power bar. Make sure the coil is not on.
3. Turn on the TV and the VCR.
4. Follow the configuration instructions on the slip of paper next to the TV.

Script

1. Bring the magnet close to the screen. The colours should distort.
2. Turn on the degaussing coil and wave it around parallel to the screen, gradually backing away from the TV. The screen should return to normal.
   

Additional Resources