Question

When 5 V potential difference is applied across a wire of length 0.1 m. The drift speed of electrons is `2.5 xx 10^(-4) ms^(-1)`. If the electron density in the wire is `8 xx10^(28) m^(-3)`, calculate the resistivity of the material of wire

Answer 1

Here, `V=5V , l = 0.1 m`,
`v_(d) =2.5 xx 10^(-4) ms^(-1),n=8xx10^(28) ms^(-3)`
As `V=RI = (rho l)/(A) xx (n A e v_(d))= rho l n e v_(d)`
or `rho =V/(l n e v_(d))`
`5/(0.1 xx (8xx10^(28))xx(1.6 xx 10^(-19))(2.5 xx 10^(-4)))`
`=1.56 xx 10^(-8) Omega m`