JEE PYQ: Solid State Question 16
Question 16 - 2019 (12 Apr Shift 1)
An element has a face-centred cubic (fcc) structure with a cell edge of $a$. The distance between the centres of two nearest tetrahedral voids in the lattice is:
(1) $\sqrt{2},a$
(2) $a$
(3) $\dfrac{a}{2}$
(4) $\dfrac{3}{2}a$
Show Answer
Answer: (3)
Solution
In FCC, tetrahedral voids are located on the body diagonal at a distance of $\dfrac{\sqrt{3},a}{4}$ from the corner. Together they form a smaller cube of edge length $\dfrac{a}{2}$. Therefore, distance between centres of two nearest tetrahedral voids in the lattice is also $\dfrac{a}{2}$.
BETA
