21. A primitive rectangular unit cell has a = 2Å, b = 3Å, and c = 90°, respectively.
A new unit cell is chosen with the edges defined by the vectors from the origin
to the points with coordinates 2, 0 and 0, 3. The number of lattice points in the
new unit cell is:
(a) 2
(b) 4
(c) 6
(d) 8
22. The side of a primitive square unit cell is, a = 2Å. A new unit cell is chosen
with the edges defined by the vectors from the origin to the points with
coordinates 1, 0 and 0, 3. Area of the new unit cell is:
(a) 12 Å
2
(b) 10 Å
2
(c) 8 Å
2
(d) 6 Å
2
23. The side of a primitive square unit cell is, a = 2Å. A new unit cell is chosen
with the edges defined by the vectors from the origin to the points with
coordinates 1, 0 and 0, 3. The number of lattice points in the new unit cell is:
(a) 2
(b) 3
(c) 4
(d) 5
24. A primitive orthorhombic unit cell has a = 5Å, b = 6Å and c = 7Å; a = b =
= 90°. A new unit cell is chosen with the edges defined by the vectors from the
origin to the points with coordinates 3, 1, 0; 1, 2, 0 and 0, 0, 1. Volume of the
new unit cell is:
(a) 1020 Å
2
(b) 1030 Å
2
(c) 1040 Å
2
(d) 1050 Å
2
25. A primitive orthorhombic unit cell has a = 5Å, b = 6Å and c = 7Å; a = b =
= 90°. A new unit cell is chosen with the edges defined by the vectors from the
origin to the points with coordinates 3, 1, 0; 1, 2, 0 and 0, 0, 1. The number of
lattice points in the new unit cell is:
(a) 2
(b) 3
(c) 4
(d) 5
38
1 Unit Cell Composition