Question: A wire has a resistance of 12 Ω and is made of a material with a resistivity of 3 x 10^-6 Ω·m. If the length of the wire is 4 m, what is its cross-sectional area?
Options:
Correct Answer: 1 mm²
Solution:
A = ρ * (L / R) = 3 x 10^-6 * (4 / 12) = 1 mm².