21. |
Which of the following compound has highest melting point ?
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Answer:
Option (a) |
22. |
What is the percentage of empty space in ccp and bcc structures ?
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Answer:
Option (c) |
23. |
The correct statement about the crystal structure of zinc blende is _____
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Answer:
Option (b) |
24. |
In crystal structure of MgO, ionic radius of each of Mg2+ and O2- is respectively 0.0659 and 0.139 nm. What will be the position of Mg2+ ions ?
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Answer:
Option (a) |
25. |
For hexagonal crystal syestem which of the following sets of parameters of axial distances and axial angles is correct ?
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Answer:
Option (d) |
26. |
Crystal system having axial distance a ≠ b ≠ c and axial angle α ≠ β ≠ γ ≠ 90° is _____ .
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Answer:
Option (b) |
27. |
Which of the following is not an example of tetragonal crystal system ?
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Answer:
Option (d) |
28. |
In a unit cell, the relation between the edge of the cube (a) and the radius of the particle (r) in fcc, bcc and simple cubic lattice is respectively _____ .
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Answer:
Option (b) |
29. |
In the crystal of a compound formed by elements A and B, atoms of A are at the corners of the cube and atoms of B are at the centres of the faces. What should be the formula of this compound ?
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Answer:
Option (c) |
30. |
Select from the following the correct set of fractions of constituents (atoms, ions and molecules) associated respectively with corners, edges and faces to form crystal lattice points in a crystal.
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Answer:
Option (a) |