Massachusetts Institute of Technology
Sign in

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

A solenoid is connected to AC power. First, a 10,000-turn coil is placed over the solenoid, but is not connected to the power source. However, the solenoid still induces current in coil, creating very high voltages because of the high number of turns. The rabbit ear spark gap creates an arc that moves from the bottom of the gap to the top (an effect known as Jacob's Ladder). This is due to convection and will not work upside-down

Next, a 1-turn copper loop (containing a gap filled by a nail) is placed over the solenoid. This time the induced current is very large, rather than the voltage. This high current encounters strong resistance in the nail creating temperatures so hot that the nail is melted.

Comments (3)

SUBJECT: MIT Physics Demo — Jacob's Ladder and the Melting Nail

Hi I would like to duplicate your setup for presentation to my students. May I please have the details of your setup and where I can buy parts? Please email me at winapps2@i-manila.com.ph

Posted over 7 years by Anonymous User

What's the voltage value of the AC source, and how much voltage and current are we talking about that are induced in the secondary coil? — Dishanker Raj

Posted over 7 years by Anonymous User

Hi there, I am interested in presenting a similar demonstration and was after the details of this experiment. Would you please email me ASAP at tmar9082@uni.sydney.edu.au. Thank you very much.

Posted almost 7 years by tmar9082

You need to log in, in order to post comments.

MIT Department of Physics Technical Services Group

MIT Department of Physics Technical Services Group

Category: Science | Updated almost 6 years ago

Created
April 09, 2008 13:50
Category
Tags
License
Creative Commons Attribution-NonCommercial (What is this?)
Additional Files


Viewed
55709 times

More from MIT Department of Physics Technical Services Group

MIT Physics Demo -- Inductor Radio

MIT Physics Demo -- Inductor Radio

Added 8 years ago | 00:01:02 | 35583 views

MIT Physics Demo -- Dipole Antenna

MIT Physics Demo -- Dipole Antenna

Added 8 years ago | 00:00:57 | 43426 views

Fire Extinguisher on a Tricycle

Fire Extinguisher on a Tricycle

Added over 7 years ago | 00:00:53 | 39944 views

The Coriolis Effect

The Coriolis Effect

Added almost 7 years ago | 00:03:00 | 88188 views

MIT Physics Demo -- Conductivity of Ionized Water

MIT Physics Demo -- Conductivity of...

Added 8 years ago | 00:00:53 | 49627 views

MIT Physics Demo -- Low Friction Atwood Machine

MIT Physics Demo -- Low Friction At...

Added almost 8 years ago | 00:00:46 | 49823 views