Thursday, July 23, 2009
"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.
See the original video on MIT TechTV - http://techtv.mit.edu/file/1104/"
From: MIT youtube channel
0 Comentários
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.
See the original video on MIT TechTV - http://techtv.mit.edu/file/1104/"
From: MIT youtube channel
0 Comentários
Postagens populares
-
"Explanation: What would it look like to travel across the known universe? To help humanity visualize this, the American Museum of Nat...
-
Physics demonstration of Pascal principle using plastic bottles
-
Privacy Policy for http://sciencevideosblog.blogspot.com/ The privacy of our visitors to http://sciencevideosblog.blogspot.com is importan...
-
Here we have another example of science experiments that uses surface tension to works. Spread peppers in a plate full of water as the...
-
What this video shows seems a magic trick but is pure science! Baking soda (sodium bicarbonate) when is mixed up with vinegar (acetic acid...
-
When two materials are rubbed a kind of effect appears, they become charged. The polarity (what material will become positive and what wil...
-
Ok, now I'm gonna tell you how to build a cool science experiment. It's called the balloon that doesn't pop, or if you would ...
-
How does a lightning form? And how does it behave? These two questions are hard to answer because the lightning happens so fast that we ...
-
The concentrated sulfuric acid can take the water out of the sugar molecule producing coal plus water according to reaction equation: C1...
-
Learn more about Infra Red Vision and how does it influence our life.
