Question

The dimensions of a rectangular parallelepiped are $1cm\times 1cm\times 100cm$. If its specific resistance is $3\times {10}^{-7}\Omega m$ then the resistance between its rectangular faces will be

• A. $3\times {10}^{-9}\Omega$
• B. $3\times {10}^{-7}\Omega$
• C. $3\times {10}^{-5}\Omega$
• D. $3\times {10}^{-3}\Omega$

Answer 1

The correct option is B $3\times {10}^{-7}\Omega$

For parallelopipped the Length would be $0.01m$ and whereas the area would be $1\times 100=100c{m}^2=0.01m^2$
i.e.
$R=\frac{\rho L}{A}=\frac{3\times {10}^{-7}\times 0.01}{0.01}=3\times {10}^{-7}\Omega$