What will be the resistance of a metal wire of length 2 metres and area of cross-section 1.55 x 10^-6 m², if the resistivity of the metal be 2.8 x 10^-8 Ω m ?

A wire is 1.0 m long, 0.2 mm in diameter and has a resistance of 10 Q. Calculate the resistivity of its material?

Write down an expression for the resistance of a metallic wire in terms of the resistivity.

Give two examples of substances which are good conductors of electricity. Why do you think they are good conductors of electricity?

Calculate the resistance of a copper wire 1.0 km long and 0.50 mm diameter if the resistivity of copper is 1.7×10^-8 Ω m.