Solving Ampere's Law Trouble: My Mistake in Calculating B?

  • Thread starter Thread starter giladsof
  • Start date Start date
  • Tags Tags
    Ampere's law Law
AI Thread Summary
The discussion revolves around a misunderstanding of Ampere's Law and the calculation of the magnetic field (B) around a current-carrying wire. The original poster questions whether B is constant within a fixed rectangle. User ehild clarifies that while the direction of B changes, its magnitude remains constant in the rectangle. Additionally, ehild explains that for a long straight wire, the magnetic field strength is inversely proportional to the distance from the wire (B is proportional to 1/r). This highlights the importance of correctly applying Ampere's Law in calculations involving magnetic fields.
giladsof
Messages
13
Reaction score
0
DNJ0W.jpg


Where is my mistake? I have a feeling it's in the calculation of B... ?
 
Last edited:
Physics news on Phys.org
Do you mean that B is constant inside the rectangle?

ehild
 
It's a given that the rectangle is fixed to the ground..

So apart from the fact that the magnetic field in it changes direction all the time, B's size is constant
 
So you say that the magnetic field of a current carrying wire does not depend on the distance from the wire?

ehild
 
For a long straight wire, B is proportional to 1/r.
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'Collision of a bullet on a rod-string system: query'

Thread 'Collision of a bullet on a rod-string system: query'

In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Importance/Use of Gauss' Law and Ampere's Circuital Law
Replies
30
Views
1K
Magnetic field due to a long, straight wire
Replies
3
Views
1K
Finding magnetic field using Ampere's Circuital Law
Replies
5
Views
928
Magnetic energy density, self-inductance of coaxial cylindrical shells
Replies
10
Views
1K
Correct usage of Ampère's law for calculating B-field outside parallel wires?
Replies
4
Views
1K
Ampere's Law Problem: B-Field from a Current Distribution
Replies
6
Views
2K
How do we obtain an ampere-hour rating given voltage and watt-hour?
Replies
4
Views
1K
Magnitude of magnetic field at different points near a capacitor.
Replies
6
Views
899
An iron cylinder inside a solenoid
Replies
4
Views
2K
Ampere's Law and Choosing a Loop for Integration
Replies
3
Views
2K

Hot Threads

Recent Insights

Back
Top