Q24. e) The resistance of a metal wire of length 1m is 26Ω at 20⸰C. if the diameter of the wire is 0.3mn, what will be the resistivity of the metal at that temperature? 3 years ago e) Given in question : l = 1m , R = 26Ω r = d/2 = 0.3/2 = 0.15mm = 0.15×10-3m We know that, ρ = R×A/l ρ= 1.83×10-6Ωm .