Question

The space occupied by b.c.c. arrangement is approximately..........

(A) 50%

(B) 68%

(C) 74%

(D) 56%

Answer 1

Correct answer is: (B) 68%

Volume of unit cell =\(\cfrac{64r^3}{3\sqrt{3}}\)

Volume occupied =\(\cfrac{8}{3}\pi r^3\)

Volume occupied by two atoms in unit cell or

packing = \(\cfrac{8}{3}\pi r^3\)\(\times\)\(\cfrac{3\sqrt{3}}{64r^3}\times100=68.04\) %