List of top Engineering Materials Science Questions

TTT diagram of a eutectoid steel is shown below. Match the heat treatment cycle (in Column I) with its microstructure (in Column II).

Which of the following statement(s) is/are true for an optical microscope?

Among the 14 Bravais lattices, there is no base-centred cubic unit cell. Which of the following statement(s) is/are true?

In a semiconductor, the ratio of electronic mobility to hole mobility is 10. The density of electrons and holes are $10^{15}$ m$^{-3}$ and $10^{16}$ m$^{-3}$, respectively. If the conductivity is $1.6 \ \Omega^{-1}$ m$^{-1}$, then the mobility of holes is $________________ \ (m^2 V^{-1} s^{-1})$. Given: $q = 1.6 \times 10^{-19}$ C

A screw dislocation in a FCC crystal has Burgers vector of $\frac{a}{2}[110]$, where $a$ is the lattice constant. The possible slip plane(s) is/are:

The tensile true stress ($\sigma$) – true strain ($\varepsilon$) curve follows the Hollomon equation: \[ \sigma = 500 \, \varepsilon^{0.15} \ \text{MPa} \] At the maximum load, the work-hardening rate $\left(\frac{d\sigma}{d\varepsilon}\right)$ is (in MPa):

A student performed X-ray diffraction experiment on a FCC polycrystalline pure metal. The following $\sin^2 \theta$ values were calculated from the diffraction peaks: \[ \sin^2 \theta = 0.136,\; 0.185,\; 0.504,\; 0.544 \] However, the student was negligent and missed noting one of the peaks. Which one of the following Miller indices corresponds to the missing peak?

Match the lattice planes and directions (in Column I) with the corresponding Miller indices (in Column II):

In age-hardening of an aluminium alloy, the purpose of solution treatment followed by quenching is to

The magnetization (M) – magnetic field (H) curves for four different materials are given below. Which one of these materials is most suitable for use as a permanent magnet?

The band gap of a semiconducting material is $\sim 2$ eV. Which one of the following absorption (A) vs. energy (in eV) curves is correct?

Figures (i) and (ii) show a binary phase diagram and the corresponding Gibbs free energy (G) vs. composition ($X_B$) diagram, respectively. Figure (ii) corresponds to which one of the temperatures shown in Figure (i)?

Aliovalent doping of $MgCl_2$ in $NaCl$ leads to the formation of defects. Which one of the following is the correct defect reaction?

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: The higher percentage of tricalcium silicate in cement results in rapid hardening with an early gain in strength at higher heat of hydration. 
Reason R: A higher percentage of dicalcium silicate in cement results in slow hardening and less heat and hydration and greater resistance to chemical attack. 
In the light of the above statements, choose the most appropriate answer from the options given below