Manipal MET2014PhysicsUnits and Dimensions
Number of particles is given by n=-D n₂-n₁ x₂-x₁ crossing a unit area perpendicular to X -axis is unit time, where n₁ and n₂ are number of particles per unit volume for the value of x meant to x₂ and x₁ . Find dimensions of D called as diffusion constant.
Options
- A[M^0 L T^2 ]
- B[M^0 L^2 T⁻⁴ ]
- C[M^0 L T⁻³ ]
- D[M^0 L^2 T⁻¹ ]
Correct answer
D. [M^0 L^2 T⁻¹ ]
Step-by-step solution
Given, number of particle passing from unit area in unit time =n= Number of particle A t = [ M ^0 ~L ^0 ~T ^0 ] [ L ^2 ][ T ] = [ L ⁻² ~T ⁻¹ ] [n₁ ]= [n₂ ]= Number of particle in unit volume = [L⁻³ ] Now, from the given formula [D]= [n] [x₂-x₁ ] [n₂-n₁ ] = . [L⁻² T⁻¹ ][L ] [L⁻³ ] = [L^2 T⁻¹ ]