GATE Metallurgical Engineering Practice Quiz

Question 1

A substitutional solid solution of element B in element A is expected to have extensive solubility if the Hume-Rothery rules are reasonably satisfied. Which one of the following pairs is the most favorable for extensive substitutional solubility?

Accepted Answer

Same crystal structure, atomic size difference less than $15\%$, similar electronegativity and same valency

Question 2

For an edge dislocation, the Burgers vector $\vec{b}$ is:

Accepted Answer

Perpendicular to the dislocation line

Question 3

In a binary eutectic system, at the eutectic temperature and eutectic composition, the invariant reaction on cooling is:

Accepted Answer

$L \rightarrow \alpha + \beta$

Question 4

For diffusion in a solid, the diffusivity follows $D = D_0\exp\left(-\frac{Q}{RT}\right)$. If the temperature is increased from $T_1$ to $T_2$, which one of the following expressions gives $\ln\left(\frac{D_2}{D_1}\right)$?

Accepted Answer

$\frac{Q}{R}\left(\frac{1}{T_1}-\frac{1}{T_2}\right)$

Question 5

For the reduction reaction $MO(s)+C(s)\rightarrow M(s)+CO(g)$, assuming pure condensed phases and ideal gas behavior, the equilibrium constant $K$ is:

Accepted Answer

$K=p_{CO}$

GATE Metallurgical Engineering

Practice Quizzes

GATE Metallurgical Engineering Practice Quiz

Iron-Carbon Phase Diagram Fundamentals | GATE Metallurgical Engineering