Question

Calculate the radius of the wire of conductance `10 Omega^(-1)` and length `10 cm` whose electrical conductivity is `10^(3) Sm^(-1)`

Answer 1

Correct Answer - `1.78 mm`
Here,`G = 10 Omega^(-1), 1 = 10 cm = 0.10 m`
`sigma= 10^(3) Omega m^(-1)`
`sigma = (1)/(rho) = (l)/(pir^(2)R) = (lG)/(pir^(2)) or r = sqrt((lG)/(pi sigma))`
`:. r = sqrt((0.10 xx 10)/(314 xx 10^(3))) = 1.78 xx 10^(-2)m = 0.0178 "m"`