Experimental procedure

Materials: Current source, voltmeter, wires of different lengths and cross sections (same material), calipers, meter stick, leads.

• Measure the diameter of each of the three wires (four measurements, take the average): https://youtube.com/shorts/j4Hfb-GNnWg

Diameter Wire 1 = ________ mm

Diameter Wire 2 = ___1.03____ mm

Diameter Wire 3 = ________ mm

• Connect each of the three wires successively to the current source. Apply different currents for each measurement randomly.

Refer to https://youtu.be/e5LNJSc0ht8 to:

• Measure the current through the wire, I.
• Measure the potential difference, V, between two random locations on the wire, situated distance L apart.
• Fill out the table below (Wire 2 starts at the 2:12 mark, Wire 3 starts at the 3:48 mark).

Experimental results. A few results are included as reference.

Wire	Diameter (mm)	Cross section area (m2)	I (A)	V (V)	L (m)	J (A/m2)	E (V/m)
1			0.512	0.444	0.40
1			0.641			1184710
1			0.074		0.28
1			0.240
2	1.03	8.33 x 10-7	0.231	0.129	0.40	277235	0.3233
2	1.03	8.33 x 10-7	0.408
2	1.03	8.33 x 10-7	0.602		0.50
3			0.231	0.0541	0.40
3			0.455
3			0.722
3			1.113				0.661

• In an Excel spreadsheet, type in the values for E (V/m) and j (A/m²). Plot j vs. E. If you are not comfortable with Excel, plot on (graph) paper.
• Fit the data with a linear function.
• Regardless of the method chosen, extract resistivity from the slope by matching the trendline (a linear function) with Equation 5 (also a linear function).

= ___________ m

• Do an online search and identify the material.

Material: _________________

• Calculate the percent difference between the measured and the theoretical values.

= ________ %