Lab 5 excel sheet

could anyone pleasee help me calculate the constant on the sheet i've tried so many things and I dont get what im doing wrong. this is what ive been using


(4*pi*k'*N)^2
(2(a^2)(4/5)^3

Hey the equation is : (4*pi'*N)^2 / (2*((5/4)^3)*a^2) you just reversed the 5 and 4 i think.

I forgot the k', not pi' but u had that right anyway! whoops

constant = ((4*pi*k'*130)^2)/(2((5/4)^3)*(a^2)

where 130 = N (it says it in the lab - this made me go crazy until I actually read the damn thing lol). It turned green in my excel sheet, so it should work in yours! (comes out to a value with E-07).

I am not getting a...
I am using a=((a_v1+a_v2)+(a_h1+a_h2))/4
What am I doing wrong?

How do you get Delta(Ir)^2??????????

how do u get : error of slope? e/m? error of e/m? error of constant? I have been plugging in so many numbers, nothing is working. thanks!

Error of e/m would be

sqrt((Δconstant/constant)^2+(Δslope/slope)^2)*e/m

Ok for the error in slope our TA told us that somthing around 15000 would work (10000 to 20000, somewhere in that range) but for some reason the excel sheet doesnt want to accept that..

Error in the constant = 2*(Δa/a)*constant

e/m = (V/(IR)^2)/constant = slope/constant

Does anyone know what textbook value of e/m refers to?

I played around with the error of slope for a bit and found that values between 500-700 seem to fit. If you put in values around there, see which max/min lines fit your error bars the best and that should be your error in slope

e/m= charge of electron/mass of electron= (1.6*10^-19)/(9.11*10-31)= 1.76E11 C/kg

How do you find the error slope? Every1 that is saying plugg-in #'s from 100-700 is WRONGGGGGG. Help me

for error in slope:

(delta(Ir)^2/(Ir)^2) * slope value

Hi

How do u find "a" and "Delta r" plz help

what #'s do i plugg-in b/c I tired 2 already and it is not working

how do you calculate the e/m value in the excel sheet? the equation in the above post doesnt make sense to me..thanks

a =(a_v1+a_v2+a_h1+a_h2)/2/4
delta r=0.002 from the error lab

e/m= slope/constant
slope you get it from the graph, try putting in the number from the graph Y= Slopex+ number
constant is just (4*pi*(10^-7)*130)^2)/(2*(5/4)^3*(a^2))

I still cannot get any of these numbers to turn green!!! e/m, error of slope, error of e/m, error of constant!!! nothing is working!!!

So I tried everything, from the equation that a previous comment to plugging in about 50 different numbers, lets just say I can not get the Slope Error to save my life.

My slope is 63436, pretty huge to me... What can I do? I really need help with this one, because ABSOLUTELY NOTHING IS WORKING!

Does anyone know how to find this value?

someone posted this equation for error in slope:

for error in slope:

(delta(Ir)^2/(Ir)^2) * slope value

but which value of delta(Ir)^2 and which value of (Ir)^2 are you using?

I tried all of them, and tried the average of the max and minimum too with no luck =/

any thoughts, please? thanks

hey guys, were you able to get the questions for execution sheet 1?

Look at the sketch of the magnetic field lines due to a single current loop. (See Ch18 sheet 26)
Use that sketch and the sketch below to help explain whether simply doubling the magnetic field of one coil is an under estimate or an over estimate of the magnetic field of interest.


Notice that the correct equation (2) and the incorrect equation differ only by a correction factor of 1/(5/4)^(3/2). When this correction factor is applied to equation does it increase or decrease the field? Does this agree with your answer above?


- for the first one, is it an overestimate because it doesn't account for the doubling of a in the denominator?

- for the second one, the correct equation decreases the field by a factor of 1/(5/4)^(3/2)

I can't tell if my logic is correct o.o

thanks for your time

i used the first values off of my excel sheet for both delta(Ir)^2 and (Ir)^2 and multiplied that answer by the value i got for my slope which you get directly off your graph (the # before the "x") ...for me my #s were (.0022/.0121) x 9988 = 1816 --> that is my error in slope..it worked for me so maybe your #s for delta(Ir)^2 and (Ir)^2 aren't correct..check to make sure you did the math right for that before plugging those #s into the error equation.

delta(Ir)^2 was given to you in the lab prep assignment...

sqrt((deltar/r)^2) * (2*(Ir)^2)