Laboratory Notes

Introduction

Here are notes that I needed to write down for some of the Lab Sessions. I was closer to a PC than my log book at the time, so I wrote them on my web page!

PC Lab Sessions

1A

Mean

10.0498

Standard Deviation

1.228575

Minimum

7.422419

Maximum

14.217

2A

Radius of copper wire

0.005m ±

Assessed Work

Data points removed as obvious outliers

1. Length = 0.721; R = 0.077; Mass = 1.016
2. Length = 1.440; R = 0.237; Mass = 0.723
3. Length = 1.024; R = 0.277; Mass = 0.723
4. Length = 0.381; R = 0.298; Mass = 0.972

Data points removed due to failing the ±3 standard residual test

1. Length = 0.381; R = 0.298; Mass = 0.972

Forcing line through the origin

I have decided to force the line through the origin because the error in the y-intercept value (0.0649) is considerably larger than the y-intercept itself (0.0099). This comparison is the standard statistical method of deciding if a line should be forced through the origin, as per Lab Session 2A.

The Resistivity of Copper

The final gradient (R/L), as found by Excel: 0.219 ± 0.0012.

The radius of the copper wire, as calculated in Lab Session 2A: see above

R = p l/(πr²)

R/L × (πr²) = p

...where R/L is the gradient. This gives

p = 1.72 × 10 ^-5