Magnetic field at the center of the loop

Click For Summary

Homework Help Overview

The discussion revolves around calculating the magnetic field at the center of a loop, specifically considering the contributions from both the loop and a long straight wire. The original poster expresses frustration over incorrect answers despite multiple attempts using different formulas.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • The original poster attempts to apply various formulas for magnetic fields but encounters discrepancies in their results. They question whether the loop can be treated as a single loop solenoid and consider the possibility of the magnetic field canceling out.

Discussion Status

Some participants have provided insights, suggesting that the magnetic field from the long straight wire should not be neglected and that superposition of the magnetic fields from both sources is necessary. However, there is no clear consensus or resolution yet.

Contextual Notes

The original poster mentions specific values for current and radius, and there is an indication of imposed homework expectations regarding the understanding of electromagnetic concepts.

Heart
Messages
39
Reaction score
0
:confused:

Here's the question:
"What is the magnetic field at the center of the loop in the figure?"

OK, the question is really simple and it looks easy. However, when I put in the answer, it's wrong. I tried different methods/formulas but still got the wrong answers. Anyone cares to enlighten me?

First, I used the formula B = I(mju_0)N/2R:
- I is 5A
- mju_0 is 4pi * 10^-7
- N is 1
- R is 0.01 m
The wrong answer was 3.14×10-4 T.

I then tried modified B = (2*10^-7)I/R (I multiplied this equation w/ some whole numbers to account for the multi directions of the field - which I then realized that it was the wrong way) I still got the wrong answers.

I then think, hell, the field might cancel out to zero, which was still wrong. (Obviously, the field was in one direction.)

PLEASE HELP. I'm desperate. :cry:
 

Attachments

  • 3254.jpg
    3254.jpg
    5.2 KB · Views: 606
Physics news on Phys.org
Anyone? What I don't get is I cannot treat it as a single loop solenoid? If not then what method should I use?

Please help.
 
It's not just a single loop. Don't neglect the field from the long straight wire.
 
people on this board do not seem to know a lot about electromagnetic. I posted two questions and so far no replies yet.
 
Doc Al provided an answer. We expect students to do their homework.

The key is superposition of two magnetic fields due to the long straight wire and the loop.

Meanwhile, we'll take a look at the other questions.
 
Last edited:

Similar threads

What is the net force on the current loop?
  • · Replies 8 ·
Replies
8
Views
2K
Induced current and force on circular loop in varying magnetic field
  • · Replies 4 ·
Replies
4
Views
2K
Magnetic field due to a coil wound on a hemsiphere
  • · Replies 6 ·
Replies
6
Views
2K
Direction and magnitude of electric field produced by current change
  • · Replies 8 ·
Replies
8
Views
2K
Current in a current-carrying loop experiencing no torque
  • · Replies 1 ·
Replies
1
Views
1K
Calculating magnetic field outside a solenoid
  • · Replies 15 ·
Replies
15
Views
2K
Understanding Torque in a Magnetic Field with Loop
  • · Replies 37 ·
2
Replies
37
Views
5K
Direction of the magnetic needle
  • · Replies 11 ·
Replies
11
Views
3K
Derivation Of Torque On Current Loop Due To Uniform Magnetic Field
  • · Replies 4 ·
Replies
4
Views
2K
Find magnetic field at center of rotating sphere
  • · Replies 9 ·
Replies
9
Views
2K