Question
Thu May 24, 2012

# calculate the resistivity of the material of a wire 1m long and 0.4mm in diameter and having resistance of 2 ohm ?

Fri May 25, 2012
s l = 1m,   r = 0.2m.m = 0.2Ã—10-3m, R = 2  ohm S = ?
from formula R = Sl/A

Sl/ A= kr2

We have S= kr2 /R = kÃ— (0.2 Ã—10-3)2Ã—2 = 2.5Ã—10-17 ohm m
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