Question

Using SI conventions, the capacitance per unit length of a coaxial capacitor is χ= 2πε0 ,

ln(b/a)

where ε0 = 8.854 × 10−12 F m−1, a is the outer radius of the inner conductor and b is the inner radius of the outer conductor. The following data were measured for a and b:

a (cm) 3.63 3.62 3.62 3.65 3.64 3.62 b (cm) 4.03 4.07 4.02 4.06 4.02 4.04

Using the standard error for your estimate of the errors in a and b, and the method of equation (45), determine χ with an error estimate. Repeat, using the method of equation (47).

Answer 1

Ans=

	a		b
	3.63		4.03
	3.62		4.07
	3.62		4.02
	3.65		4.06
	3.64		4.02
	3.62		4.04
n1	6	n2	6
s1	0.01265	s2	0.02098
SE1	0.00516	SE2	0.00856
	ln(b/a)	0.50580046
	chi	2.8142E-11

I calculate standard deviations of a and b both data in excel using excel command STDV.S( )

then later I calculate standard errors by formula

then calculate ln(b/a) by excel command LN(b/a)

and then calculate chi=2*pi*e0*ln(b/a)