What is the resistance of a 90-cmcm-long piece of carbon with a 2.0 mmmm ×× 2.0 mmmm square cross section?

A certain metal has a resistivity of 13.6×108 m at 20°C. the temperature coefficient of the given material is 0.00392°C, what will be the resistivity at 850°C.

Problem 3: A 1.2 g wire has a density of 2.7 g/cm3 and a resistivity of 2.7 × 10−8 Ωm. The wire has a resistance of 15 Ω. a) How long is the wire? b) The wire is made up of atoms with valence 1 and molar mass 26.98 g/mol. What is the drift speed of the electrons when there is a voltage drop of 30 V across the wire?

Kiting during a storm. The legend that Benjamin Franklin flew a kite as a storm approached is only a legend — he was neither stupid nor suicidal. Suppose a kite string of radius 2.10 mm extends directly upward by 0.802 km and is coated with a 0.520 mm layer of water having resistivity 155 Ω·m. If the potential difference between the two ends of the string is 176 MV, what is the current through the water layer? The danger is not this current but the chance that the string draws a lightning strike, which can have a current as large as 500 000 A (way beyond just being lethal).