List of top Material Science and Technology Questions

A load of \(4.0 \, \text{kg}\) is suspended from a ceiling fan through a steel wire of radius \(2.0 \, \text{mm}\). The tensile stress developed in the wire when equilibrium is achieved is: (Take \(g = 9.81 \, \text{m/s}^2\)):
An aluminum crystal is bent into a radius of curvature of 5 cm. The minimum dislocation density in the material is (Burgers vector = \(3 \, \text{\AA}\)):
Gold and Platinum both have FCC structures with unit cell dimensions of \(4.08 \, \text{\AA}\) and \(3.91 \, \text{\AA}\), respectively. The metallic radii of atoms are:
The number of symmetry elements in a cube are:
The angle between [111] and [001] directions in a cubic crystal is:
In a crystal, a plane cuts intercepts of 2a, 3b, and 6c along three crystallographic axes. The Miller Indices for the plane are:
The frequency of X-ray emitted by an X-ray tube operating at 30 kV is
100 calories of heat is given to a gas in a vessel fitted with a movable piston. The gas does 40 joules of work in expansion. The increase in internal energy is
100 g of water is slowly heated from 27◦C to 87◦C. The change in entropy of water is (Specific heat capacity of water = 4200 J/kg/K)
The planar density for (010) and (020) planes in simple cubic Polonium, which has a lattice parameter of 0.334 nm, is
Copper has an FCC crystal structure and a unit cell with a lattice constant of \(0.361 \, \text{nm}\). The interplanar spacing \(d_{111}\) is:
The interplanar spacing for cubic materials is given by the equation
The packing factor for diamond cubic silicon is
The primitive translation vectors of a two-dimensional lattice are \(\bm{a} = 2\bm{i} + \bm{j}\) and \(\bm{b} = 2\bm{j}\). The primitive translation vectors of its reciprocal lattice \(\bm{a}^*\) and \(\bm{b}^*\) are:
An X-ray tube operates at 20 kV, and a particular electron loses 5% of its kinetic energy to emit an X-ray photon at the first collision. The wavelength corresponding to this photon is
In an FCC unit cell, the number of lattice points is
The packing factor for the FCC unit cell is
The BCC iron, which has a lattice parameter of 0.2866 nm, has a density of
Iron at 20◦C is BCC with atoms of atomic radius 0.124 nm. The lattice constant a for the cube edge of the unit cell is
The relationship between atomic radius (r) and lattice parameters (a) for a simple cubic (SC) structure is
The ratio of the number of vacancies to the number of atoms when the average energy required to create a vacancy is 0.9 eV at 400K is
Silica exhibits ionic and covalent bonding and the fraction of covalent bonding is (Electronegativity of Silicon is 1.8 and that of Oxygen is 3.5)
The bond responsible between atoms and molecules which determine the surface tension and boiling point of liquids is
The length of Burgers vector b in copper (Cu), which has an FCC crystal structure, is
The number of vacancies per cm\(^3\) in a BCC iron crystal having density of 7.87 g/cm\(^3\) and lattice parameter of \(2.866 \times 10^{-8} \, \text{cm}\) is: