question_answer 83)

  The correct order of the packing efficiency in different types of unit cells is.......... (a) fee < bcc < simple cubic         (b) fee > bee > simple cubic (c) fee < bcc > simple cubic         (d) bcc < fee > simple cubic

Answer:

                  (b) Packing efficiency in different types of unit cells can be tabulated as

Unit cell	Packing efficiency
fee bcc Simple cubic	74% 68% 52%

  Hence, correct order is fee (74%) > bcc (68%) > simple cubic (52%).