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.

Options

A. `M^(0)LT^(2)`
B. `M^(0)L^(2)T^(-4)`
C. `M^(0)LT^(-3)`
D. `M^(0)L^(2)T^(-1)`

Answer

d

Explanation

`[n] =` Number of particles crossing a unit area in unit time `= [L^(-2)T^(-1)]`
`[n_(2)] = [n_(1)]=` number of particle per unit volume `= [L^(3)]`
`[x_(2)] = [x_(1)] = "positions" = [L]`
`:. D = ([n][x_(2) - x_(1)])/([n_(2) - n_(1)]) = ([L^(-2)T^(-1)] xx [L])/([L^(-1)]) = [L^(2)T^(-1)]`.