Question

Percentage of free space in cubic close packed structure and in body centred packed structure are respectively ___________.

• A. $30\%and26\%$
• B. $26\%and32\%$
• C. $48\%and48\%$
• D. $32\%and26\%$

Answer 1

The correct option is B $26\%and32\%$

The packing efficiency in a ccp structure = 74%

Therefore, Percentage free space = 100 – 74 = 26%

Packing efficiency in a body centred structure = 68%

Therefore, Percentage free space = 100 – 68 = 32%