Same chapter3 marksDifficulty: Medium
How many atoms are there in a face-centred cubic unit cell?
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3 marksDifficulty: Medium
Calculate the packing efficiency of a face-centred cubic lattice.
Original Khojo Papers practice question — not from a past board paper.
Answer
74%
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
An fcc unit cell contains 4 atoms and the relation between the edge a and the radius r is a = 2√2 r. The fraction occupied is 4 × (4/3)πr3 ÷ a3, which works out at about 0.74.
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