A2 experiment and I'm totally confused

  • Context: High School 
  • Thread starter Thread starter sexysam_short
  • Start date Start date
  • Tags Tags
    Confused Experiment
Click For Summary

Discussion Overview

The discussion revolves around the interpretation of results from an A2 experiment involving the dropping of a magnet through a coil and the resulting induced voltage measured with a data logger. Participants explore the nature of the induced voltage, its waveform, and the underlying principles of electromagnetic induction.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Sam describes the experiment and notes the appearance of a sine wave in the voltage graph when the magnet passes through the coil, expressing confusion about this observation.
  • Another participant questions the mechanism behind the induced voltage, asking what causes the current to be induced in the coil.
  • A participant references Faraday's law, explaining that the changing magnetic field lines linked with the coil induce current due to the movement of electrons, suggesting that the induced voltage is related to the sine function due to the angle of alignment.
  • Sam seeks clarification on why the graph shows negative voltage after the positive peak, indicating a need for further understanding of the waveform behavior.
  • Another participant explains that the positive sine wave corresponds to the magnet being centered in the coil, while the negative voltage occurs as the magnetic field collapses when the magnet exits, suggesting a phase relationship between the induced voltage and the magnetic field changes.

Areas of Agreement / Disagreement

Participants express varying levels of understanding regarding the induced voltage and its waveform. While some explanations are provided, there is no consensus on the complete interpretation of the results or the underlying mechanisms.

Contextual Notes

Some assumptions about the behavior of magnetic fields and induced currents are not fully explored, and the discussion lacks resolution on the specifics of the sine wave behavior and its implications.

Who May Find This Useful

This discussion may be useful for students or individuals interested in electromagnetic induction, experimental physics, and the interpretation of experimental data related to voltage induction in coils.

sexysam_short
Hello!

I've recently done an A2 experiment and I'm totally confused as to how to interpret the results! I would be really greatful for some help!

I basically droped a magnet through a coil and measured the voltage with a data logger and what not! I get that there's an induced voltage, because it's a magnet being dropped through a coil, but the graph looks like a sine wave at the point when the magnet is passing through the coil. Why does it?

Thanks lots,

Sam
 
Physics news on Phys.org
Why is a voltage induced when the magnet passes through the coil? Current is induced in the coil in response to what...?
 
As you might know that the described phenomena was discovered by M. faraday.
When a bar magnet is droped in coil the magnetic field lines, associated with the magnet, linkage with the coil change. It cause change in magnetic field changing magnetic field force electron in the coil to move, as the force is same on all eceltrons and in same direction they start flowing and the current is induced.
As the force on electrons is dependent on sinx (x is angle of allingment) the induced current hence voltage are sin functions.
 
Thanks for the help! But, I get why it would be the positive part of the sine wave, because of the induced currect, but why does the graph go negative?
 
Me again (changed my username because I thought this word was fantastic! lol)

I've just realized I actually don't know how you get an induced current? Could someone please explain it to me?!

Thanks lots!
 
You get the positive sine as more of the magnet is centered in the coil ending when the magnet is centered and the coil is saturated ( to the extent of the available magnetic field from the magnet)..conversly when the magnet exits the v approaches 0 . The coil has a stored magnetic field and when that field collapses the expressed V is 180 degrees out of phase with the V induced by the magnet. Thats why we use a protection diode on a relay coil reversed biased and why use a ballast resistor on a car coil.
 

Similar threads

  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 42 ·
2
Replies
42
Views
4K
  • · Replies 16 ·
Replies
16
Views
5K
  • · Replies 12 ·
Replies
12
Views
3K
  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 9 ·
Replies
9
Views
6K
  • · Replies 2 ·
Replies
2
Views
2K