Confirming Faraday's Law - interference in measurement.

AI Thread Summary
The discussion focuses on an experiment aimed at confirming Faraday's Law by measuring the EMF generated from a rotating magnet inside a solenoid. The experimenter observed disturbances in the EMF graph and seeks to understand potential causes for this noise. Suggestions include the possibility of motor vibrations affecting the measurements and issues related to the connection between the magnet and the motor. The need for more detailed experimental setup information is emphasized to better diagnose the interference. Overall, the conversation highlights the complexities of accurately measuring EMF in such experiments.
peripatein
Messages
868
Reaction score
0
Hi,

Homework Statement


We ran an experiment for confirming the linearity of Faraday's Law (the relation between EMF and the rate of change of flux), by plugging a magnet to a motor rotating in the axis of a solenoid (inductor). In my graph of the amplitude of EMF wrt time, I noticed some disturbances on a few of the peaks. What might have been the causes of such interference("noise")?
I'd appreciate some insight, please.

Homework Equations





The Attempt at a Solution

 
Physics news on Phys.org
You might give some more details of your experiment. What do you mean by "plugging a magnet to a motor rotating in the axis of a solenoid (inductor)." Are you changing the speed of the motor or just plotting the emf vs time. How are you measuring the emf, a scope?
 
We were measuring the EMF produced as a result of the rotating magnet inside the solenoid, by changing the angular frequency of the rotation (the speed of the motor). Hence, for various frequencies we obtained various EMFs. I cannot tell for sure, I fear, whether the device used to measure the EMF was a scope.
Is it nevertheless clearer now? Could you assist?
 
I agree with barryj, you need to describe the setup in detail. For example, the solenoid has inductance and a 'scope has capacitance, which might result in peaking somewhere. Etc.
 
I am not really sure how to provide more details than I already have. We might have indeed used a scope, and it's highly likely we did, but I couldn't vouch for that. Anything else?
 
I am merely interested in the possible, most probable causes for the interferences ("noises") shown in the graphs, as a means of explaining them.
 
peripatein said:
I am merely interested in the possible, most probable causes for the interferences ("noises") shown in the graphs, as a means of explaining them.

So how about showing us the data? We can't perform an autopsy without a body ... :smile:
 
Please see attachment. Y axis is EMF, X axis is time. I hope this will suffice :)
 

Attachments

  • Untitled.jpg
    Untitled.jpg
    33.6 KB · Views: 357
As a guess, I'd suspect motor vibrations. The noise is not random, that's for sure. And the "plugging" of the magnet into the motor, that connection might have some slop in it.

About the best I can do I'm afraid.
 

Similar threads

Magnetic energy density, self-inductance of coaxial cylindrical shells
Replies
10
Views
1K
Lenz's Law and Faraday's Law clarification
Replies
11
Views
2K
Current in circular wire surrounding infinite solenoid in a circuit
Replies
7
Views
1K
Induced EMF in a circle: Faraday's law
Replies
11
Views
3K
Faraday's Law: Induced Voltage and Current in a Loop with Resistance R
Replies
3
Views
2K
EMF induced in a coil encircling an ideal solenoid
Replies
2
Views
2K
Calculating Induced EMF using Faraday's Law: A Magnetic Flux Problem Solved
Replies
5
Views
4K
What is the Correct Approach for Solving Faraday's Law Problem?
Replies
5
Views
2K
SAT II Physics -- Induced current in loop (Faraday's law)
Replies
8
Views
3K
What happens when a piece of iron is put into an inductor?
Replies
10
Views
7K

Hot Threads

Recent Insights

Back
Top