Resistance and Resistivity
Purpose of the lab is to verify
l
(1)
A
where l is the length, A is the cross-sectional area, and ρ is the resistivity for a single piece of nichrome 60 wire. The manufacturer publishes that
R=ρ
26 gauge: 2.67 Ω/ft.
30 gauge: 6.75 Ω/ft.
40 gauge: 70.2 Ω/ft.
so, from these numbers and (1) one can calculate ρknown in Ω-m.
For each of the 3 gauges, and a about 2.5m of wire each,
1. graph R vs l/A (maybe one line and a lot of points)
2. graph R vs. l (three lines - one for each A)
3. graph R vs 1/A (5 lines - one for each length)
From graph 1, extract ρ and unc, compare to ρknown to get error, validate (1) by comparing to unc.
Do a full write-up for this one.