Highly selective Backlog Qs for JEE MainPhysicsUnits and Dimensions
Number of particles, given by n = - D n 2 - n 1 x 2 - x 1 , is crossing a unit area perpendicular to x -axis in unit time, where n 1 and n 2 are number of particles per unit volume for the value of x meant to x 2 and x 1 . Find dimensions of D , called as diffusion constant.
Options
- AM 0 L T 2
- BM 0 L 2 T - 4
- CM 0 L T - 3
- DM 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 = N u m b e r o f p a r t i c l e A × t = M 0 L 0 T 0 L 2 T = L - 2 T - 1 n 1 = n 2 = N u m b e r o f p a r t i c l e i n u n i t v o l u m e = L - 3 Now, from the given formula D = n x 2 - x 1 n 2 - n 1 = L - 2 T - 1 L L - 3 = L 2 T - 1