How do I find the uncertainty in this specific scenario?

[Hao2k]

Homework Statement

The task is to find the uncertainty of the magnetic field, B. The magnetic force is plotted against current, so that the slope of the resulting line of best fit is LB, where L is the length of the conductor and theta is constant at 90 degrees (thus sin(theta) = 1). The uncertainty of slope is found using the LINEST function in Excel.

The magnetic force, current, and length all have their own uncertainties while the slope also has a uncertainty.

Homework Equations

F = ILBsin(theta)

The Attempt at a Solution

B = m/L
so the uncertainty of B (dB) would be:

dB = sqrt(dBm^2 + dBL^2)

where dBm is the uncertainty of B due to m and dBL is the uncertainty of B due to L.

What I am not sure of, I suppose, is the calculation of dBm. m is the slope of the graph, but it is also F/I, so would that mean that the total uncertainty of m would include both the uncertainty of m due to F and I, and the uncertainty of m due to the fluctuation of the data points on the graph? If so, then would the value of the uncertainty of m be:

dm = sqrt(dmF^2 + dmI^2 + dm_fluc^2)

By the way, sorry if this is the wrong category, because I am unsure of where this goes. Thank you!

 

[mfb]

If (!) your excel function takes the uncertainties into account properly, you don't have to worry about force and current uncertainties any more.
You'll have to check the documentation what it does.

It is a mathematics question but with strong physics connections. Should work here.