Current produced by a single charge moving in a circlular motion

AI Thread Summary
The discussion revolves around calculating the magnetic field produced by an electron moving in a circular path around a proton, as described in Bohr's model of the hydrogen atom. The participant expresses confusion regarding the derivation of the current and the application of the Biot-Savart law, particularly the absence of pi in the magnetic field equation for a circular loop. They question how to determine the time it takes for the electron to complete one orbit, which is essential for calculating current. The participant acknowledges their misunderstanding and recognizes the need to review the concepts more thoroughly. Overall, the conversation highlights the complexities of applying theoretical physics to practical calculations in atomic models.
Benkyou
Messages
7
Reaction score
0

Homework Statement



In Niels Bohr's 1913 model of the hydrogen atom an electron circles the proton at a distance "R" with a speed "v". Compute the magnitude of the magnetic field that this motion produces at the location of the proton.

Homework Equations



Bio Savart

B = mu*I / 2R = mu * q * (v/2piR) / 2R


The Attempt at a Solution



The solution is stated above in the relevant equations section.

There are some misunderstandings I have as to how they arrived at the equation for the current.

First the magnetic field given by an infinite wire should be mu*I/2*pi* r but is shown as it is above without the pi in the denominator. Further, I thought that the moving charge should have a current that is equivalent to its velocity, charge, and cross sectional area ( I = nqvA ), but that is not what is correct. I feel as if I'm missing the big pink elephant in the room that is related to the period of the of charge or something. Can someone give me some help?
 
Physics news on Phys.org
I'm sorry the magnetic field in the center of a current loop is B = mu*I / 2*R. I guess I don't understand how the current is being calculated.
 
Current is given by
I = Q/t
So current is due to the charge of one electron, moving in a circular loop.
To get t in the equation, how much time does it take the charge to make a complete orbit around the loop?

p.s. also, note the formula for a long straight wire does not apply here, since the current is in the form of a circular loop.
 
Redbelly98 said:
Current is given by
I = Q/t
So current is due to the charge of one electron, moving in a circular loop.
To get t in the equation, how much time does it take the charge to make a complete orbit around the loop?

p.s. also, note the formula for a long straight wire does not apply here, since the current is in the form of a circular loop.

Geez I don't know why I couldn't figure it out. That makes so much sense and its so simple. I think I just need to go over the material a lot more and try to understand the concepts better. Thanks a lot I appreciate the help.
 
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