Crystal A diffracts from (111) and (200) planes but not from (110) plane, while the crystal B diffracts from (110) and (200) planes but not from the $(111)$ plane. From the above, we may conclude that
(a)A has fcc lattice while B has bcc lattice
(b)A has bcc lattice while B has fee lattice
(c)A and B both have fcc lattice
(d)A and B both have bcc lattice.
Answer
Answer: A ✓ checked by 4AB · confidence high
Explanation
fcc reflections need h, k, l all odd or all even ((111), (200) present, (110) absent); bcc needs h + k + l even ((110), (200) present, (111) absent). A is fcc, B is bcc.