Question

5. . Calculate the total resistance of a 50 metre roll of 2.5mm˄2 copper wire if the resistivity of copper is 1.2 x 10˄-8 Ω metre.​

Answer 1

Answer:

where R is resistance in ohm, ρ is resistivity in Ω-metre, l is length in metre & A is cross sectional area in m^2.

Given,

ρ = 1.7 * 10^-6 Ω-metre

l = 2,000 metre (2 km)

A = π*r^2 = π*(0.0005/2)^2 m^2 = 1.9635 * 10^-7 m^2

(Since 0.5 mm= 0.0005 m & Radius is half of diameter)

So,

R= (1.7 * 10^-6 )* 2000 / (1.9635 * 10^-7) Ω

or, R= 17,316.05 Ω or 17.316 kΩ

Answer 2

Explanation:

when ferrous metals corrode. Rust is the common name for the chemicals that result when iron reacts with oxygen and water. ... We do not speak of silver or copper “rusting.” Inst