The number of particles is given by `n = -D(n_(2) - n_(1))/( x_(2) - x_(1))` crossing a unit area perpendicular to X - axis in unit time , where `n_(1)and n_(2)` are particles per unit volume for the value of `x` meant to `x_(2) and x_(1)` . Find the dimensions of `D` called diffusion constant.

Answer

`[L^2 T^(-1)]`

Explanation

From `n = -D((n_2 - n_1)/(x_2 -x_1))`
`D =(n(x_2 - x_1))/(-(n_2 - n_1))`
Dimesions of n= number// area// time
` =L^(-2) T^(-1)`
`Dimesions of `n_1, n_2 = "number"//" volume" = L^(-3)`
Dimensions of `x_2 -x_1` = diff. between two
positons = L
`:. D = ((L^(-2)T^(-1)(L))/(L^(-3)) = [L^2 T^(-1)]`