18. The number of crystallogaphically equivalent directions in the <100> family of
a tetragonal crystal system is:
(a) 4
(b) 6
(c) 8
(d) 12
19. The number of crystallogaphically equivalent directions in the <110> family of
a tetragonal crystal system is:
(a) 4
(b) 6
(c) 8
(d) 12
20. The number of crystallogaphically equivalent directions in the <101> or
<011> family of a tetragonal crystal system is:
(a) 4
(b) 6
(c) 8
(d) 12
21. The number of crystallogaphically equivalent directions in the <111> family of
a tetragonal crystal system is:
(a) 4
(b) 6
(c) 8
(d) 12
22. The Miller indices of the line of intersection of the planes 1 1 1
ð
Þ and 1 11
ð
Þ are:
(a) [011] or 0 1 1
½
(b) [101] or 10 1
½
(c) [110] or 1 10
½
(d) 10 1
½
or 101
½
23. The Miller indices of the line of intersection of the planes (110) and (111) are:
(a) [011] or 0 1 1
½
(b) [101] or 10 1
½
(c) [110] or 1 10
½
(d) 1 10
½
or 101
½
172
4 Unit Cell Representations of Miller Indices
a tetragonal crystal system is:
(a) 4
(b) 6
(c) 8
(d) 12
19. The number of crystallogaphically equivalent directions in the <110> family of
a tetragonal crystal system is:
(a) 4
(b) 6
(c) 8
(d) 12
20. The number of crystallogaphically equivalent directions in the <101> or
<011> family of a tetragonal crystal system is:
(a) 4
(b) 6
(c) 8
(d) 12
21. The number of crystallogaphically equivalent directions in the <111> family of
a tetragonal crystal system is:
(a) 4
(b) 6
(c) 8
(d) 12
22. The Miller indices of the line of intersection of the planes 1 1 1
ð
Þ and 1 11
ð
Þ are:
(a) [011] or 0 1 1
½
(b) [101] or 10 1
½
(c) [110] or 1 10
½
(d) 10 1
½
or 101
½
23. The Miller indices of the line of intersection of the planes (110) and (111) are:
(a) [011] or 0 1 1
½
(b) [101] or 10 1
½
(c) [110] or 1 10
½
(d) 1 10
½
or 101
½
172
4 Unit Cell Representations of Miller Indices