Question

Compute the electrical conductivity of cylindrical silicon specimen 5.1 mm (0.2 in.) in diameter and 51 mm (2 in.) in length in which a current of 0.1 A passes in an axial direction. A voltage of 12.5 V is measured across two probes that are separated by 38 mm (1.5 in.).

Answer 1

Answer:

Therefore electric conductivity $\sigma$=1.46  (Ω-m)⁻¹

Explanation:

$\sigma=\frac{1}{\rho} =\frac{Il}{VA}$

Here σ= electrical conductivity

        $I$ = current = 0.1 A

        $l$= length= 38 mm= 38×10⁻³ m

       v= voltage = 12.5 V

      A = area = $\pi(\frac{d}{2} )^{2}$ = $\pi (\frac{51\times 10^{-3}}{2} )^2$ m²

$\sigma=\frac{(0.1)\times 38\times 10^{-3}}{12.5\times \pi (\frac{51\times 10^{-3}}{2} )^2 }$

  =1.46 (Ω-m)⁻¹

Therefore electric conductivity $\sigma$=1.46  (Ω-m)⁻¹