Massachusetts Institute of Technology
Sign in Create Account

Fluorescent and Neon Tubes in an Electric Field

A fluorescent tube swings at the end of a long plexiglass rod. It is made to rotate and then brought near the Van de Graaff generator. The tube lights up when there is a potential difference between its ends. This happens when it is pointing radially away from the Van de Graaff. The same can be done with a small neon tube.

Comments (3)

Hi, Can any one explain how the energy is conserved in this case?? Where does the neon, tube gets the energy?? I mean its an electric field but there is no current flow from the generator in this case and the circuit is open in the case of the tubes..

Posted 4 years by subramaniann

The possibility that I could think of is that the electrons/Ions in the tube is aligning itself due to electric field and in turn causes the tube to glow.. but in this case at one point it should stop glowing once the capacitor is fully charged… and since the tube is rotating it should continuously glow as the capacitor gets constantly charged and discharged/or charged in reverse direction

Posted 4 years by subramaniann

There should be a force acting on the tubes too due to electrostatic repulsion and attraction on the electrons and ions!!!

Posted 4 years by subramaniann

You need to log in, in order to post comments. If you don’t have an account yet, sign up now!

MIT Department of Physics Technical Services Group

MIT Department of Physics Technical Services Group

Category: Science | Updated almost 2 years ago

Created
March 16, 2010 13:44
Category
Tags
License
Creative Commons Attribution-NonCommercial (What is this?)
Additional Files


Viewed
35261 times

More from MIT Department of Physics Technical Services Group

Moving Sand Cart Over a Rotating Surface

Moving Sand Cart Over a Rotating Su...

Added almost 6 years ago | 00:01:13 | 34402 views

MIT Physics Demo -- Low Friction Atwood Machine

MIT Physics Demo -- Low Friction At...

Added over 6 years ago | 00:00:46 | 47644 views

Breaking Glass with Sound

Breaking Glass with Sound

Added 6 years ago | 00:02:33 | 59848 views

Lenz's Law with Copper Pipe

Lenz's Law with Copper Pipe

Added 3 years ago | 00:01:38 | 7704 views

Spray Paint Oscillator

Spray Paint Oscillator

Added over 6 years ago | 00:00:51 | 28187 views

Hinged Stick and a Falling Ball

Hinged Stick and a Falling Ball

Added almost 5 years ago | 00:01:23 | 20250 views