# Worksheet: Electrical Conductivity and Resistivity

In this worksheet, we will practice calculating the electrical resistance of a material given its resistivity, cross-sectional area, and length.

**Q6: **

Coils are often used in electric and electronic circuits.
A particular coil is formed by winding 500 turns of insulated
30 gauge copper wire in a single layer on a cylindrical
non-conducting core of radius
1.00 mm.
The wire’s cross-sectional area is
0.0510 mm^{2},
which includes the negligible area of the insulation.
Find the resistance of the coil.
Use a value of
Ω⋅m
for the resistivity of copper.

**Q8: **

Consider two cables, one made of copper and one made of aluminum. Both are 15.00 m long, and the copper cable has a resistance of 0.035 Ω.
In determining the electrical and mechanical properties of the cables, use a value of 8,960 kg/m^{3} for the density of copper and
Ω⋅m for its resistivity. Use a value of 2,760 kg/m^{3} for the density
of aluminum and Ω⋅m for its resistivity.

What is the weight of the copper cable?

What is the weight of the aluminum cable?

What is the resistance of the aluminum cable?