Question

The physical quantity having the dimensions $\left[ M ^{-1} L ^{-3} T ^{3} A ^{2}\right]$ is

• A. resistance
• B. resistivity
• C. electrical conductivity
• D. electromotive force

Answer 1

Answer: (C)

electrical conductivity

Answer 2

Resistivity, $\rho=\frac{m}{n e^{2} \tau}$ $\because [\rho] =\frac{[ M ]}{\left[ L ^{-3}\right][ AT ]^{2}[ T ]}$ $=\left[ ML ^{3} A ^{-2} T ^{-3}\right]$ So, electrical conductivity, $\sigma=\frac{1}{\rho}$ ${[\sigma]=\frac{1}{[\rho]}=\left[ M ^{-1} L ^{-3} A ^{2} T ^{3}\right]}$