Match List I with List II
| List I | List II |
| (A) Simple and face centred cubic | (I) \(a = b = c\) |
| (B) Cubic and rhombohedral | (II) \(\alpha = \beta = \gamma = 90^o\) |
| (C) Cubic and tetragonal | (III) have only two crystallographic angle of \(90^o\) |
| (D) Hexagonal and monoclinic | (IV) belong to the same crystalline system |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → (A)-(IV), (B)-(I), (C)-(II), (D)-(III)
(A) Simple and face centred cubic — This matches (IV) belong to the same crystalline system. Primitive (simple), body-centred and face-centred cells are the possible variations of the cubic system.
(B) Cubic and rhombohedral — This matches (I) \(a = b = c\). Both have three equal edges. They differ in the angles: cubic has α = β = γ = 90°, rhombohedral has α = β = γ ≠ 90°.
(C) Cubic and tetragonal — This matches (II) \(\alpha = \beta = \gamma = 90^o\). Both have all three angles of 90°. They differ in the edges: cubic a = b = c, tetragonal a = b ≠ c.
(D) Hexagonal and monoclinic — This matches (III) have only two crystallographic angle of \(90^o\). Hexagonal: α = β = 90°, γ = 120°. Monoclinic: α = γ = 90°, β ≠ 90°. Each has two angles of 90° and one that is not.
Note: This question is from the pre-rationalised NCERT book (2022-23). The topic is not there in the latest NCERT book (2026-27), and it is also out of the CUET 2026 syllabus.
NCERT (Pre-rationalised edition, 2022-23):
Primitive and Centred Unit Cells
