GATE 2025 PI – Question 20

General Engineering · Engineering Materials · 1 mark · Multiple choice

The atomic packing factor of a body-centered cubic crystal is closest to ______.

Show answer and explanation

Correct answer: (C) 0.68

Explanation

BCC has two atoms per unit cell and $\sqrt3a=4r$. Thus packing fraction $=2(4\pi r^3/3)/a^3=\pi\sqrt3/8\approx0.6802$. **C**.

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