You should listen intently to ION, as he is 100% correct, and you are leading yourself astray once again.
Here are some corrections for you to consider:
a) In Lewin's original setup, and the one I tested, the E field is what is directly inducing the loop current, not the B field.
b) In your toroid setup, the B field is what is inducing the loop current.
c) When going around the loop to reconcile all the measured voltages, we ADD them, not subtract them as you did in your first video. In other words, the SUM of the series voltages in a loop is zero. The SUM of your two resistor measurements is 80.3mV. (see e) below)
d) Proper measurement of the wire part of the loop is done around the outside of the toroid, and if you account for the polarity and voltage, you will find that when added to the other two resistor voltages, you will be left with something close to zero.
e) Your "proper" measurement of the toroid section of the wire was about 81mV. The two resistor voltages summed is 73mV + 7.3mV = 80.3mV. Summed with the series-subtracting wire voltage leaves you with 0.7mV.
KVL holds.
Poynt
I need to address these issue's with you,as i think you really need to take another look at this.
So far,here are some of the events that have taken place in this thread.
In reply 28,you highlighted a quote from Matt-Watts -->
When dealing with B fields, your position of measurement matters. To which you replied-->
Precisely.Then in reply 30 you state--
a) In Lewin's original setup, and the one I tested, the E field is what is directly inducing the loop current, not the B field.It is my belief that both the E and B field played a part in the Lewin circuit,and i will get to that later,after i have assembled Lewins original test setup along side mine.
In post 11 i state-->
the secondary loop is induced by the electric field,and not the magnetic field.In post 30 you also state this--
b) In your toroid setup, the B field is what is inducing the loop current.In post 31 i state--
Im going to disagree with you Poynt,and i think you have it backwards.
In Lewins setup,it is the B field cutting through the loop.
In my setup,the B field is contained within the toroid.Then in reply 45 you state-
After some reflection on the toroid configuration, I am in agreement that the E field is the action mechanism on the wire loop. However, in the solenoid configuration (the original one), again it is the E field that acts upon the loop.I am happy that you agree with me about it being the E field that is inducing the current in my loop,as that means all my hard work and time in gaining an understanding into all forms of induction, by way of being self taught and my time spent on the bench,and my own thought's is paying off.
Now,while i wish to remain focused mainly on my toroid setup,i would like to reflect a little on Lewins original setup.
You state it is the E field inducing the single loop,but you also seem to agree with Matt as well when he says--
When dealing with B fields, your position of measurement mattersNow,the way i see it(these are my thought's),the E field is inducing the current through the secondary loop of Lewins setup,and the B field is inducing the voltage in the loops of the measuring equipment leads.
I confirmed this on my bench-->the E field will not induce a current in the secondary loop when that secondary loop is not around the circumference of the primary coil. If the secondary loop is sitting beside the primary,and not wrapped around the primary coil,no current will be induced via the E field.
Now,this is not the case with the B field,where the secondary loop will be induced if that secondary loop is sitting beside the primary coil,and not wrapped around it.
In saying all that,here is the problem i see in the testing of Lewin's circuit.
The secondary loop is induced by the E field(as you state),but the measuring equipment leads were induced by the B field !apparently!,in accordance with your reply to Matts comment regarding the B field-->
When dealing with B fields, your position of measurement matters,to which you reply !Precisely!
Now the biggest problem here is the phase relationship between the induced voltage of the secondary loop by the E field,and the induced voltage of the measurement equipment leads by the B field.
These two induced voltages should have been 90* out of phase,but in your tests,they were all in phase
How do we know this?
Well if it is the E field inducing the EMF in the secondary,then the primary and secondary voltage phase relationship should be in phase. If it is the B field inducing the EMF in the secondary,then voltage phase relationship between the primary and secondary should be 90*,as the magnetic field in the primary is a result of current flow,and we know the current lags the voltage by 90* in an inductor.
So i have to wonder,which voltage the measurement equipment was actually measuring?.
Was it the voltage across the resistors in the secondary loop induced by the E field,or the induced voltage in the third loop formed by the measurement equipments lead's which was induced by the B field?.
And what is the outcome of mixing two different circuits,where 1 has an in phase relationship with the primary inductor's voltage,and the other has a 90* phase relationship with the primary inductor's voltage.
If i am wrong about all this,could you please explain as to why you agree with Matts comment about the B field,but state it is the E field that is inducing the EMF in Lewin's experiment ?.
Thanks
Brad
Never let your schooling get in the way of your education.
Author
Topic: Kirchhoff is for the birds... (Read 27205 times)
