Induced emf in a solenoid from a current carrying wire nearby

Click For Summary

Discussion Overview

The discussion revolves around the induced electromotive force (emf) in a solenoid placed in the vicinity of a current-carrying wire, particularly focusing on how the solenoid's characteristics, such as its radius, influence the measured emf. The scope includes theoretical considerations and mathematical reasoning related to electromagnetic induction.

Discussion Character

  • Exploratory
  • Technical explanation
  • Mathematical reasoning

Main Points Raised

  • One participant inquires about the induced emf in a solenoid subjected to an external magnetic field described by Bo Sin(ωt) and expresses interest in how the solenoid's characteristics affect the measured emf.
  • Another participant suggests calculating the magnetic fields separately and superposing them, indicating a method to analyze the situation based on the solenoid's orientation.
  • A participant expresses confusion about the previous response, asserting that there is only one external magnetic field and speculating that the solenoid's radius would influence the induced emf, seeking clarification on this relationship.
  • One participant acknowledges the importance of the solenoid's current and resistance, suggesting that a low resistance in parallel with the solenoid could lead to higher power output from a fixed input power.
  • It is mentioned that the inductance of the solenoid plays a role in the relationship between current and emf, with a claim that increasing the solenoid current decreases the magnetic flux through it, resulting in a lower induced emf.

Areas of Agreement / Disagreement

Participants express differing views on the relationship between the solenoid's characteristics and the induced emf, with some proposing calculations and methods while others seek clarification on the effects of the solenoid's size and current. The discussion remains unresolved regarding the precise nature of these relationships.

Contextual Notes

There are limitations in the assumptions made regarding the magnetic fields and their interactions, as well as the dependence on the definitions of terms like inductance and emf. The mathematical steps involved in the calculations are not fully resolved.

silentstorm
Messages
4
Reaction score
0
Say I have a solenoid that has a magnetic field Bo Sin(ωt) passing through its axis. What will be the EMF induced in the solenoid as a result ? I know it'll be a function of Cos (ωt) but I am more interested in how my choice of the solenoid will affect the EMF that I'll ultimately measure.

Thanks in advance!
 
Physics news on Phys.org
Calculate the fields separately and supperpose them. If the solenoid axis is parallel to z-axis, you can calculate the field for the wire first and add the solenoid field to its z-component.
 
Hassan, thanks for the response, but I don't understand what you mean. There is only one field here which is an external magnetic field. If you put a solenoid into a magnetic field, I am guessing the size (Radius) of the solenoid would affect the induced EMF ? I am interested in knowing what that relation would be.
 
silentstorm said:
Hassan, thanks for the response, but I don't understand what you mean. There is only one field here which is an external magnetic field. If you put a solenoid into a magnetic field, I am guessing the size (Radius) of the solenoid would affect the induced EMF ? I am interested in knowing what that relation would be.

Sorry I misread your question!

But your question,

Yes you are right. If it had no effect, the emf would be independent of the solenoid current. So by choosing a low resistance parallel with the slenoid we would get very high power from a fixed input power!

The effect is infact what we know as the inductace of the solenoid.
In order to calculate the current and emf when you have current in the coil, just imagine a voltage source in series with the inductance and the load. Calculation beomes simple then.

Added: The interaction is so that by increasing the solenoid current, the flux passing though it decrease and this results a lowe emf.
 

Similar threads

Undergrad Questions about cancelation of induced EMF and minimizing eddy currents
  • · Replies 4 ·
Replies
4
Views
2K
Undergrad EMF induced in a straight current-carrying conductor
  • · Replies 9 ·
Replies
9
Views
3K
Undergrad The EMF induced in straight current-carrying conductor
  • · Replies 10 ·
Replies
10
Views
4K
Undergrad Can a Strong Magnet Induce EMF in a Copper Wire Solenoid from a Distance?
  • · Replies 3 ·
Replies
3
Views
2K
Graduate Induced current in a coil from a constant uniform magnetic field?
  • · Replies 5 ·
Replies
5
Views
2K
Graduate Current induced from a changing magnetic field
  • · Replies 2 ·
Replies
2
Views
2K
Drop height of a magnet vs. induced EMF in a solenoid
  • · Replies 41 ·
2
Replies
41
Views
9K
High School Experiment issues (electromagnetism)
  • · Replies 42 ·
2
Replies
42
Views
4K
Graduate Inducing currents without change of flux linkage?
  • · Replies 3 ·
Replies
3
Views
2K
Graduate Electric Fields with Motional EMF
  • · Replies 20 ·
Replies
20
Views
2K