1. The problem statement, all variables and given/known data Calculate the resistance of a strand of aluminium wire of diameter 4.0mm and length 1.0m, given its resistivity is 2.5*10^-8 Ωm. What would be the resistance per meter of 50 strands of this wire, using the strands in parallel as a cable? 2. Relevant equations ∏d^2/4 for area ρ=RA/L, Where ρ = Given resistivity R= Resistance A= Cross sectional Area L= Length 3. The attempt at a solution 4.00mm Diameter → 4*10^-3 Converted to Meters Length = 1m Resistivity = 2.5*10^-8 Ωm So I found out the Area using ∏d^2/4;∏*(4*10^-3)/4 which = 1.26*10^-5 m^2 Then I used the formula ρ=RA/L, rearranging for R, ρL/A = R and subbing in the values; 2.5*10^-8 * 1 /1.26*10^-5 which gives an answer of 1.989*10^-3 Ωm^-1 thus i multiplied it by 50 which gives a final answer of 0.09945 However my answer differs from the answer of the book which is given as 4.99Ωm^-1 Thanks for any help!