Match each material in Group I with a bond type in Group II.

Group I	Group II
P. Silicon	1. Metallic bonding
Q. Copper	2. Covalant bonding
R. Sodium chloride	3. Ionic bonding
	4. Vander-Wallis bonding

When the wavelength of the incident X-Tay increases the angle of diffraction

A. decreases

B. increases

C. remains constant

D. shows no systematic variation

Identify the false statement.

A. Burger vector and the dislocation line are Parallel to each other for screw dislocations

B. Burger vector and the dislocation line are perpendicular to each other for edge dislocations

C. Screw dislocations glide parallel to its Burger vector

D. Edge dislocations glide parallel to its Burger Vector

A schematic of X-ray diffraction pattern of a single phase cubic polycrystal is given below. The miller idices of Peak A is

A. 210

B. 220

C. 222

D. 310

The theoretical density of an fcc metal with atomic radius and atomic weight of 0.144 nm and 197 gm.mol^-1 respectively, is approximately (in kg.m^-3)

A. 18110

B. 18300

C. 19360

D. 19890