List of top Engineering Sciences Questions on Material Science

On applying 10 V across the two ends of a 100 cm long copper wire, the average drift velocity (in cm s$^{-1}$) in the wire is (rounded off to two decimal places)............. Given:

For a pure element with a BCC crystal structure, the surface energies per unit area of $ \{100\} $ and $ \{110\} $ free surfaces are $ S_{100} $ and $ S_{110} $, respectively. The ratio, $ \frac{S_{100}}{S_{110}} $, is (rounded off to one decimal place):

Corrosion of pure iron takes place in an acidic electrolyte by forming $ {Fe}^{2+} $ ions at ambient condition. The corrosion current density is measured to be $ 2 \times 10^{-4} \, {A cm}^{-2} $. The corrosion rate (in mm per year) of iron is (rounded off to one decimal place) ............
Given: \begin{align*} {Atomic weight of iron} &= 55.85
{Density of iron} &= 7.86\ {g} \cdot {cm}^{-3}
{Number of days in a year} &= 365
1\ {Faraday} &= 96500\ {Coulomb} \cdot {mol}^{-1} \end{align*}

The standard free energy change for the reaction, $ {SO}_2 + \frac{1}{2} {O}_2 \rightleftharpoons {SO}_3 $ at equilibrium is given by $ \Delta G^\circ = -94600 + 89.37T $, where $ T $ is in Kelvin and $ \Delta G^\circ $ is in Joules. The equilibrium constant ($ K_p $) at 1050 K is (rounded off to two decimal places) ...........
Given: Universal gas constant (R) $= 8.314\ {J} \cdot {K}^{-1} \cdot {mol}^{-1}$

The slopes of reduction potential versus pH plots for the two reactions, $ {NiO} + 2{H}^+ + 2e^- \Rightarrow {Ni} + {H}_2{O} $ and $ 2{H}^+ + 2e^- \Rightarrow {H}_2 $, at 298 K and one atmospheric pressure are $ S_1 $ and $ S_2 $, respectively. The ratio $ \frac{S_1}{S_2} $ is (rounded off to one decimal place) ............

An electric field is applied on a copper plate such that the electrons are displaced by $1.1 \times 10^{-18}$ m relative to the nucleus. The electronic polarization (in $ \mu C \, {m}^{-2} $) is (rounded off to two decimal places) ...........

An aluminum transmission line of 7 km length is designed to carry 100 A current with no more than 2 MW power loss. The required minimum diameter (in mm) of the transmission line is (rounded to the two decimal places) ........... Given: Aluminum conductivity $= 3.77 \times 10^5\ \Omega^{-1} \cdot {cm}^{-1}$ % Answer Range Answer Range: Between 1.00 and 1.20

At 873 K, hydrogen diffuses under steady state condition through a 5 mm thick palladium sheet with a cross-sectional area of 0.3 m$^2$. The concentrations of hydrogen at high and low pressure ends of the sheet are 3 kg/m$^3$ and 0.5 kg/m$^3$, respectively. The amount of hydrogen (in kg per day) passing through the sheet is (rounded off to two decimal places) ............
Given: At 873 K, diffusivity of hydrogen $= 1.8 \times 10^{-8}\ {m}^2 \cdot {s}^{-1}$

A diffraction pattern is obtained from a powdered sample of a pure element, which has FCC crystal structure. If $ x $ and $ y $ are the Bragg angles of the first and the third peaks, respectively, then the ratio, $ \frac{\sin y}{\sin x} $, is (rounded off to one decimal place)........... % Answer Range Answer Range: Between 1.4 and 1.8

If solid tin is in equilibrium with its vapor, the degree of freedom is (answer in integer) ........

A GaP–GaAs semiconductor LED display has a band gap of 1.9 eV. The wavelength of emitted light in $ \mu $m is (rounded off to two decimal places) .........

Corrosion of pure iron takes place in an acidic electrolyte by forming $ {Fe}^{2+} $ ions at ambient condition. The corrosion current density is measured to be $ 2 \times 10^{-4} \, {A cm}^{-2} $. The corrosion rate (in mm per year) of iron is (rounded off to one decimal place) ............

An aluminum transmission line of 7 km length is designed to carry 100 A current with no more than 2 MW power loss. The required minimum diameter (in mm) of the transmission line is (rounded to the two decimal places) ...........

On applying 10 V across the two ends of a 100 cm long copper wire, the average drift velocity (in cm s$^{-1}$) in the wire is (rounded off to two decimal places).............

For a pure element with a BCC crystal structure, the surface energies per unit area of $ \{100\} $ and $ \{110\} $ free surfaces are $ S_{100} $ and $ S_{110} $, respectively. The ratio, $ \frac{S_{100}}{S_{110}} $, is (rounded off to one decimal place):

A diffraction pattern is obtained from a powdered sample of a pure element, which has FCC crystal structure. If $ x $ and $ y $ are the Bragg angles of the first and the third peaks, respectively, then the ratio, $ \frac{\sin y}{\sin x} $, is (rounded off to one decimal place)...........

The triple point $ (T_t, P_t) $ is shown in a schematic phase diagram (pressure (P) – temperature (T) plot) for one component system. $ G_S, G_L, G_V $ are the free energies of solid, liquid, and vapor, respectively. At a constant pressure, $ P_t $, the correct free energy $ G $ versus temperature $ T $ plot is:

Match the detector for a scanning electron microscope (SEM) in Column I with the resulting output in Column II.

In an FCC crystal with lattice parameter $ a $, consider the reaction of two leading partial dislocations, AB and CD, at the line of intersection of their slip planes $ (111) $, respectively, as shown in the figure below. Dislocations AB and CD, have Burgers vectors $ \mathbf{b_1} $ and $ \mathbf{b_2} $, respectively, as given in the figure. Which one of the following options for the slip plane and the Burgers vector of the resulting dislocation is correct?

The figure below shows a plane PQR in a unit cell. The Miller indices of the plane PQR is:

An electric field is applied on a copper plate such that the electrons are displaced by $1.1 \times 10^{-18}$ m relative to the nucleus. The electronic polarization (in $ \mu C \, {m}^{-2} $) is (rounded off to two decimal places) ...........