The packing efficiency of the two dimensional square unit cell shown below is:

Options

A. 0.3927
B. 0.6802
C. 0.7405
D. 0.7854

Explanation

`sqrt(2)L = 4r = rArr (r )/(L ) = (sqrt(2))/(4)`
Packing efficiency = `(2pi r^(2))/(L^(2)) = 2x ((1)/(2sqrt(2)))^(2) = (pi)/(4) = 78.5%` .