Finding B field within solenoid.

AI Thread Summary
The discussion focuses on calculating the magnetic field (B field) inside a solenoid with 10,000 turns per meter and a straight wire segment placed perpendicularly within it. The user attempts to apply the formulas for the magnetic field of both the solenoid and the straight wire but struggles with the variables, particularly the distance (r) for the wire. They express confusion over combining the magnetic fields from both sources and seek clarification on the correct approach. Despite multiple attempts and referencing notes, they feel stuck and unsure about their understanding of the concepts involved. The thread highlights the challenges in applying theoretical equations to practical scenarios in electromagnetism.
Alouette
Messages
35
Reaction score
0
1.
A current balance is constructed to measure the force between a solenoid with n=10000turns per length and a straight wire segment of length l=0.05m inside the solenoid and perpendicular to the field. The current through both the solenoid and wire segment is I=14A. What is the B field inside the solenoid?

2.
B = μonI (solenoid)

B = (μoI)/(2∏r) (straight wire)3.
I've gone over notes and the chapter, but seeing as I'm still struggling, would like some insight.

Drawing a diagram, on xy-plane I drew the solenoid on x-plane and since it says the wire is perpendicular to it, it is on the y-plane cutting across the solenoid.

My first attempt was to simply use the equations stated above and plug in the numbers:
μonI = (4∏ x 10^-7)*(10,000/0.05)*(14) = 3.52
Obviously wrong since it doesn't involve the straight wire segment.

Trying to use the equation for straight wire is of no use because of the r which I don't seem to have.

I go back to my drawing, RH rule suggests the wire has B field curling around it, while next to it, the solenoid's B field which loops around is there. Showing how little I know but my next thought was to add the two B fields, answer not different from first attempt. This is where I'm stuck.

Besides missing the concept, am I missing something obvious, or am I going to get the response of going to the book once again...
 
Last edited:
Physics news on Phys.org
Not even one tiny help? I'm not even looking for much.
 
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...
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...
Back
Top