Problem 3: Calculate the resistance of wire 10 m long that has a diameter of 2 mm and resistivity 2.63 * 10-2 Ω m.
Given Length of wire, L = 10 m Diameter of cross-section = 2 mm = 2 * 10-3 m
Resistivity, ρ = 2.63 * 10-2 Ω m = 0.0263 Ω m
Required Resistance of the wire, R =?
Resistance is related to the length and cross-sectional area of the wire in the following equation.
Here A is the cross-sectional area of the wire. This can be calculated by the relation
Radius is half the dia. Therefore, radius of the wire = 1 * 10-3 m
Put values in the formula (1)