Lewin's NCF Experiment and Lecture

[tinman]

Brad:

Koolaid is a powdered fruit drink mix that has been a favorite of kids over here since the 60's.

There phrase "Drink the Koolaid" comes from a tragic event where a guy named Jim Jones led a group of folks that he had brainwashed to a place in Guyana and ran the place like a drug crazed dictator.  When a US Senator went there to see if the folks were OK, he was shot and killed.  Jones then instructed his followers that God want them to drink the Koolaid with him.  The Koolaid was loaded with poison and all of them were found dead a few days later.  Everyone in the group followed this nut and did whatever he told them to do including killing themselves.



Sorry, if the above is not totally clear but, it will give you some idea of the history of this often used phrase.

Bill

PS  Next, we should talk about the phrase "Jump the shark" which comes from a Happy Days tv program episode.

So, when someone is said to have drunk the Koolaid, it simply means they have blindly accepted and followed something someone else has told them without any reasoning on their own.

Well if that is the meaning behind it,then Poynt needs to retract his comment,as i blindly followed no one. I did some research in the hope of finding answers that arose from my own test result's-as i always do. If i did not,then it could be just as easy to say that i drank the Poynt coolaid,where i blindly followed him,without researching the answers for my self.


Brad

[poynt99]

I have not used the invert switch on the scope for any of these measurements--you misunderstood what i was saying. The first scope point/polarity has to be inverted to do our loop test point measurements,as the polarity show is opposite to that needed for a series loop measurement.

I assumed these were fresh measurements, as I had suggested that you do all 4 in a row. But apparently you have not done that. You may wish to try doing them, as there is the possibility they may sum to 0V.

[poynt99]

Well if that is the meaning behind it,then Poynt needs to retract his comment,as i blindly followed no one. I did some research in the hope of finding answers that arose from my own test result's-as i always do. If i did not,then it could be just as easy to say that i drank the Poynt coolaid,where i blindly followed him,without researching the answers for my self.


Brad

You posted/quoted something that 99% of academics espouse, and I assume you take it for granted that it is correct. That is ok, as most of the time they are.

You have just proven on your bench however that they are wrong (and right, depending on the perspective).

It really comes down to defining  precisely what one is referring to when making statements about dynamic fields and KVL. Most get it all mixed up or are simply unclear or too general (like your quote). If the method of measurement isn't made, then the statement is ambiguous. It must be qualified, otherwise it is just noise.

[poynt99]

Quote-KVL is based on the assumption that there is no fluctuating magnetic field linking the closed loop.

False. You have proven this yourself. If the measurements are performed to measure the potential differences, KVL does hold.

In the presence of a changing magnetic field the electric field is not a conservative vector field.

True.

Therefore the electric field cannot be the gradient of any potential. That is to say, the line integral of the electric field around the loop is not zero, directly contradicting KVL.

True, but no one is trying to apply KVL on the E field itself; that is their incorrect assumption! So the point is moot.

When dynamic fields are the source of emf in a circuit, KVL still applies to the potential differences in the circuit.

[minnie]

Ok