For a simple cubic lattice, the ratio between the unit cell length and...
Explanation:
The separation between two adjacent parallel crystal planes is given by the Miller indices of the crystal planes. For a simple cubic lattice, the Miller indices of the crystal planes are (hkl), where h, k, and l are integers. The separation distance between two adjacent parallel crystal planes is given by the formula:
d = a / sqrt(h^2 + k^2 + l^2)
where a is the length of the unit cell.
To find the ratio between the unit cell length and the separation of two adjacent parallel crystal planes, we can divide both sides of the equation by a:
d/a = 1 / sqrt(h^2 + k^2 + l^2)
Therefore, the ratio between the unit cell length and the separation of two adjacent parallel crystal planes depends only on the Miller indices of the crystal planes.
Now, let's consider the options given in the question:
a) 5^(1/2)/2 = 1.118: This ratio can be obtained for the (111) crystal plane.
b) 7^(1/2)/2 = 1.322: This ratio can be obtained for the (110) crystal plane.
c) 11^(1/2)/2 = 1.658: This ratio can be obtained for the (100) crystal plane.
d) 13^(1/2)/2 = 1.826: This ratio cannot be obtained for any of the crystal planes in a simple cubic lattice.
Therefore, the correct answer is option 'D'.
For a simple cubic lattice, the ratio between the unit cell length and...
The answer should be B because we cannot express 7 as the sum of the squares of three coordinates