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 over 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 almost 2 years ago

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


Viewed
52176 times

More from MIT Department of Physics Technical Services Group

MIT Physics Demo -- Back "emf" in a Large Solenoid

MIT Physics Demo -- Back "emf" in a...

Added almost 7 years ago | 00:00:23 | 64162 views

MIT Physics Demo -- Dipole Antenna

MIT Physics Demo -- Dipole Antenna

Added almost 7 years ago | 00:00:57 | 40477 views

MIT Physics Demo -- Pendulum and Magnet

MIT Physics Demo -- Pendulum and Ma...

Added almost 7 years ago | 00:01:11 | 41357 views

Fluorescent and Neon Tubes in an Electric Field

Fluorescent and Neon Tubes in an El...

Added 5 years ago | 00:02:02 | 34611 views

MIT Physics Demo -- Telegraph Transmitter

MIT Physics Demo -- Telegraph Trans...

Added almost 7 years ago | 00:00:36 | 50361 views

Fiber Optic Bundle

Fiber Optic Bundle

Added almost 3 years ago | 00:01:20 | 4696 views