25-9-2003
Today I set up two experiments to find the force on a shorted loop in the field due to an alternating current in (1) single turn of wire carrying alternating current and (2) the force on the same shorted loop in a solenoid carrying alternating current.
In both cases I found no evidence of any force. If there is one then its magnitude is smaller than my apparatus can detect..
1. Single Turn
| Diagram showing balance arrangement |
a) An alternating current of about one amp was passed through a single turn of wire 50 cm in diameter and was configured with a switch so that it could be turned on and off. A shorted loop about ten cm in diameter was suspended on a balance arm pivoted some way from the loop within the single turn but above the centre. A counterbalance ensured stability.
When the current was applied there was no visible movement of the shorted loop.
2 Solenoid
Diagram similar to above.
Similarly to a) but with the shorted loop suspended near the mid point of the solenoid but above the centre axis.
When the current was applied there was no visible movement of the loop.
Conclusion:
My calculation predicting a force towards the centre under these conditions was wrong and if there is a force then it is smaller than my simple apparatus can detect.