Question

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


80

• A. 74.05%
• B. 68.02%
• C. 39.27%
• D. 78.54%

Answer 1

The correct option is D 78.54%

Packing efficiency
$=\frac{Areacoveredbtparticle}{Totalarea}=\frac{2\times \pi r^2}{a^2}=\frac{2\times \pi r^2}{(2\sqrt{2}r{)}^2}=\frac{\pi }{4}$