Engineering stress-strain curve for a metal under two conditions. A and B, are shown is the following figures. Identify the correct statement. <img src="/images/question-image/metallurgical-engineering/miscellaneous-in-metallurgy/1684344635-M2-B-19-35.PNG" title="Miscellaneous in Metallurgy mcq question image" alt="Miscellaneous in Metallurgy mcq question image">

An elliptical dislocation loop is gliding on plane ABCD of a single crystal of BCC material as shown in the following figure. It is gliding along the burger vector 'b'. Identify the correct statement.

P. Plane ABCD belongs to the family of (110).
Q. Burger vector 'b' belong to direction.
R. Dislocation has the edge character at point x and the screw character at point z.
S. Dislocation has the screw character at point x

A

P, Q

B

Q, R

C

P, R

D

P, S

The diffusion couple shown below is made from two A-B alloys. The initial compositions of the two alloys are indicated in the diagram. The centreline is at x = 0. The couple is held at an elevated temperature for 40 hours. Diffusivity; D = 3 × 10^-11 m^-2 s^-1. Assume the diffusion couple to be infinitely long.

Which of the parameters give the composition profile in the following form?
$$C\left( {x,t} \right) + {c_1} + {c_2}\,erf\left( {\frac{1}{{2\sqrt {Dt} }}} \right)$$

A

c1 = 0.45, c2 = 0.05

B

c1 = 0.5, c2 = 0.4

C

c1 = -0.05, c2 = 0.45

D

c1 = 0.1, c2 = 0.9

There are two classes of three figures each. Class 'A' figures differ in certain way from figures in Class 'B'. Which two of the four Answer Figures belong to Class 'A'?

A

1 and 3

B

1 and 2

C

2 and 4

D

2 and 3

An alloy of overall composition, X_B = 0.7 was equilibrated at temperature T₁. Microstructural analysis showed two phases, (α and β, and that the phase fraction of β was 0.75. Given that the equilibrium composition of β at Ti is 0.9 as shown in the phase diagram below, the maximum solubility of B in α (in mole fraction) at this temperature is . . . . . . . .

A

0.05

B

0.10

C

0.50

D

0.85

A furnace wall is made of three materials (I, II and III) of equal thickness and having thermal conductivity k₁ k₂ and k₃ respectively. The steady state temperature profile inside each material is shown in the figure. Thermal conductivities of the materials will vary as

A

k1 > k2 > k3

B

k2 > k1 > k3

C

k3 > k1 > k2

D

k3 > k2 > k1

A furnace wall consists of four layers of different materials, M₁, M₂, M₃ and M₄. If the layers are of equal thickness and the steady state temperature profiles is as shown below, then the material with the lowest thermal conductivity is

A

M1

B

M2

C

M3

D

M4

A simplified energy band-diagram of an intrinsic semiconductor at thermal equilibrium (300 K) is shown. In the accompanying table, which one of the four cloumns correctly represents the listed parameters? Assume same effective mass for electrons and holes.

A

<table class="table-style-1"> <tr> <td rowspan="2">Parameter</td> <td colspan="4">Energy-difference</td> </tr> <tr> <td>Column 1</td> <td>Column 2</td> <td>Column 3</td> <td>Column 4</td> </tr> <tr> <td>Band-gap</td> <td>ΔE2</td> <td>ΔE1</td> <td>ΔE2</td> <td>ΔE1</td> </tr> <tr> <td>Electron affinity</td> <td>$$\frac{{\Delta {E_1}}}{2}$$</td> <td>ΔE2 - ΔE1</td> <td>$$\frac{{\Delta {E_2}}}{2}$$</td> <td>ΔE2 - $$\left( {\frac{{\Delta {E_1}}}{2}} \right)$$</td> </tr> <tr> <td>Work function</td> <td>ΔE1 + ΔE2</td> <td>ΔE2 - $$\left( {\frac{{\Delta {E_1}}}{2}} \right)$$</td> <td>ΔE1 - $$\frac{{\Delta {E_2}}}{2}$$</td> <td>ΔE2 + $$\left( {\frac{{\Delta {E_1}}}{2}} \right)$$</td> </tr></table> Column 1

B

Column 2

C

Column 3

D

Column 4