In a conductor , if the number of conduction electron per unit volume is 8.5\times 10^{28}m^{-3}  and mean free time is 25\:fs ( femto second ) , it's approximate resistivity is : 

(m_{e}=9.1\times10^{-31}kg)

  • Option 1)

    10^{-6}\:\:\Omega\:m

  • Option 2)

    10^{-7}\:\:\Omega\:m

  • Option 3)

    10^{-8}\:\:\Omega\:m

  • Option 4)

    10^{-5}\:\:\Omega\:m

 

Answers (1)
V Vakul

 

 

Resistivity -

\rho=\frac{m}{ne^{2}\tau}

- wherein

It is independent of shape and size of the body i.e. l and A

 

 

we know that ,

\rho=\frac{m}{ne^2\tau}

\rho=\frac{9.1\times10^{-31}}{(8.5\times10^{28})(1.6\times10^{-19})^{2}(25\times10^{-15})}

\rho=\frac{9.1}{8.5\times(1.6)^{2}\times25}\times 10^{-6}\simeq 1.6\times10^{-8}


Option 1)

10^{-6}\:\:\Omega\:m

Option 2)

10^{-7}\:\:\Omega\:m

Option 3)

10^{-8}\:\:\Omega\:m

Option 4)

10^{-5}\:\:\Omega\:m

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