The Resistivity Rod Set (RRS) has several different diameter brass rods, as well as single diameter rods of aluminum, copper, music wire, and stainless steel. The Instructor notes for Lab 09 in Advanced Physics with Vernier — Beyond Mechanics (PHYS-ABM) has sample data for all rods except the stainless steel.
The stainless steel rod is made of type 303 stainless steel.
The table provides typical values for electrical resistivity and the associated resistance per unit length for the rods in this set. Note that there is some variability in resistivity depending on the specific alloy. These values are provided as a general reference.
| Electrical resistivity (Ohm – cm) | Resistance per unit length (Ohm/cm) for 1/8″ diameter rod | Resistance per unit length (Ohm/m) for 1/8″ diameter rod | |
| Brass | 6.00E-06 | 7.57E-05 | 7.57E-03 |
| Copper | 1.68E-06 | 2.12E-05 | 2.12E-03 |
| Aluminum | 2.80E-06 | 3.53E-05 | 3.53E-03 |
| Stainless Steel (303) | 7.20E-05 | 9.08E-04 | 9.08E-02 |
| Music Wire | 1.85E-05 | 2.33E-04 | 2.33E-02 |
The Music Wire is spring tempered, phosphate coated, carbon steel wire (ASTM A228). The value presented above is calculated from experimental data.