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 5 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!

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


Viewed
50851 times

More from MIT Department of Physics Technical Services Group

MIT Physics Demo -- Jacob's Ladder and the Melting Nail

MIT Physics Demo -- Jacob's Ladder ...

Added over 6 years ago | 00:01:26 | 47494 views

MIT Physics Demo -- Driven Mechanical Oscillator

MIT Physics Demo -- Driven Mechanic...

Added 6 years ago | 00:01:07 | 35642 views

Finding the Center of Mass...achusetts

Finding the Center of Mass...achusetts

Added over 3 years ago | 00:02:15 | 20793 views

Feather and Coin in a Vacuum

Feather and Coin in a Vacuum

Added over 3 years ago | 00:02:08 | 20314 views

Charge and Electric Field of a Hollow Conductor

Charge and Electric Field of a Holl...

Added almost 3 years ago | 00:01:54 | 7496 views

Fiber Optic Bundle

Fiber Optic Bundle

Added 2 years ago | 00:01:20 | 3802 views