Massachusetts Institute of Technology
Sign in | Create Account

MIT Physics Demo -- Conducting Glass

A small glass tube, held by copper wire, is placed in series with a light bulb. The glass acts as an insulator at room temperature, meaning the current cannot flow between the copper wires. This leaves an open circuit and the light bulb does not light up. Touching a conductor across the copper wires (with a metal screwdriver for instance) does complete the circuit because it allows current to flow.

However, when glass is sufficiently heated by a torch it becomes an ionic conductor. Ionic bonds in the glass are broken, allowing the charge carrying ions to move freely. Thus, when the glass is melted the current can flow, which closes the circuit and lights the bulb.

Comments (1)

That is very interesting. I never learned that glass could be conductor.

Posted almost 6 years by Anonymous User

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 over 1 year ago

Created
June 20, 2008 15:47
Category
Tags
License
Creative Commons Attribution-NonCommercial (What is this?)
Additional Files


Viewed
51038 times

More from MIT Department of Physics Technical Services Group

MIT Physics Demo -- Driven Mechanical Oscillator

MIT Physics Demo -- Driven Mechanic...

Added over 6 years ago | 00:01:07 | 35788 views

The Coriolis Effect

The Coriolis Effect

Added 5 years ago | 00:03:00 | 76132 views

Spray Paint Oscillator

Spray Paint Oscillator

Added almost 6 years ago | 00:00:51 | 27024 views

Fluorescent and Neon Tubes in an Electric Field

Fluorescent and Neon Tubes in an El...

Added over 4 years ago | 00:02:02 | 33123 views

Temperature Effect on Resistance

Temperature Effect on Resistance

Added over 5 years ago | 00:01:10 | 41934 views

DC Motor

DC Motor

Added over 1 year ago | 00:01:17 | 2308 views