Crystals MCQ Level – 2 - Physics MCQ

In a bcc structure, for any atom at the corner of the lattice, nearest neighbour is at the centre of the lattice which is at a distance of  The second nearest neighbour is at the adjacent corners of the lattice at a distance of 'a'.
The correct answer is: a

[0 1 0] is the miller indices of the plane, hence, the intercept will be   the plane is in x-z plane passing through y = 1.
Now number of atoms in the plane for simple cubic lattice is = 

⇒ Number of atoms per unit area of plane [0 1 0] of simple cubic lattice is,
 (since, a = 2r).
The correct answer is: 

The vectors of reciprocal lattice are




The correct answer is: 

 

Coordinates of pointis , hence, in crystal notation the plane is [2 2 1]
The correct answer is: [2 2 1]

Miller indices are (3, 2, 6)
Hence, crystallographic axis are

The correct answer is: (2a, 3b, c)

simple cubic → 52%, bcc → 68%, fcc → 74%, diamond → 34%, hcp 74%
The correct answer is: R and T

If is unit vector normal to the plane, then

If d is the interplanar. distance,

where  is the translation vector along one of the unit axis.
Here the planes are perpendicular to this unit axis 

The correct answer is: 

For bcc structure :




The correct answer is: 

The correct answer is Option 4: [1 1 1]. The smallest angle at which Bragg reflection can occur corresponds to a set of planes with indices [1 1 1]. This is because the interplanar spacing d of the crystal planes is equal to the unit cell dimension ao for NaCl crystals. Thus, for Bragg's law to be satisfied, the path length difference between waves effectively reflected by two adjacent planes must be equal to 2d sin 8, or mA, where m is an integer. For m = 1, the Bragg angle 8 is equal to arcsin (1/2a) which is equal to arcsin (1/2 x 0.563) = 54.7°. The Miller indices of the planes satisfying this condition are [1 1 1].

The correct answer is: