10. Total number of symmetry elements exist in a tetragonal unit cell is:
(a) 11
(b) 13
(c) 15
(d) 17
11. Total number of symmetry elements exist in a hexagonal unit cell is:
(a) 11
(b) 13
(c) 15
(d) 17
12. Total number of symmetry elements exist in a cubic unit cell is:
(a) 17
(b) 19
(c) 21
(d) 23
13. The matrix corresponding to a 2 − fold rotation along z-axis is:
(a)
À1 0 0
0 À1 0
0
0 1
0
@
1
A
(b)
À1 0 0
0 1 0
0 0 À1
0
@
1
A
(c)
1 0
0
0 À1 0
0 0 À1
0
@
1
A
(d)
À1 0
0
0 À1 0
0
0 À1
0
@
1
A
14. The matrix corresponding to a 2-fold rotation along y-axis is:
(a)
À1 0 0
0 À1 0
0
0 1
0
@
1
A
(b)
À1 0 0
0 1 0
0 0 À1
0
@
1
A
(c)
1 0
0
0 À1 0
0 0 À1
0
@
1
A
(d)
À1 0
0
0 À1 0
0
0 À1
0
@
1
A
6.3 Group (Point) Representation of Symmetry Operations
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