Metallurgical Engineering Gate 2020 Questions with Answer

Ques 27 GATE 2020

The dye penetrant test for detecting flaws is based on:

Ques 28 GATE 2020

Two solid spheres X and Y of identical diameter are made of different materials having thermal diffusivities 100 × 10^-6 m² s^-1 and 25 × 10^-6 m² s^-1 respectively. Both spheres are heated in a furnace maintained at 1000 K. If the center of the sphere X reaches 800 K in 1 hour, time required for the center of sphere Y to reach 800 K is _______.

Ques 29 GATE 2020

Select the correct spectra (shown on a log-log scale in the figures) for emission from a gray surface and a black body, both maintained at 1000 K.

A

B

C

D

Ques 30 GATE 2020

Angle between two neighboring tetrahedral bonds in Si having a diamond cubic structure is:

Ques 31 GATE 2020

The sequence of precipitation during aging of Al-4 wt.% Cu alloy is:

Ques 32 GATE 2020

The indenter used in Rockwell hardness measurements on C scale is _______.

Ques 33 GATE 2020

A heavily cold-worked metal will _______.

Ques 34 GATE 2020

A component subjected to tensile stress in a mechanical device is monitored periodically for cracks by NDT. The NDT technique can only detect cracks (both surface and internal) which are larger than 1 mm. Keeping a 10% margin of safety, the maximum allowed tensile stress on the component will be _______ MPa (round off to the nearest integer). Given, fracture toughness K_IC = 30 MPa m^1/2 and assume crack geometry factor of unity.

Ques 35 GATE 2020

An iron plate with a total exposed surface area of 50 cm² undergoes atmospheric corrosion. If 200 g of weight is lost over a period of 10 years, then the corrosion rate is _______ kg⋅m^-2⋅year^-1 (round off to the nearest integer).

Ques 36 GATE 2020

The number of atoms per unit area in (100) plane of Pb is _______ nm^-2 (round off to the nearest integer).
Given, crystal structure and atomic radius of Pb are FCC and 0.175 nm respectively.

Ques 37 GATE 2020

In the edge dislocation configuration given in the figure, dislocations X and Y are fixed and separated by a distance 2h on the same slip plane. Dislocation Z is free to glide on a parallel slip plane. The two slip planes are separated by a distance h. Which one of the following statements is TRUE regarding the stability of dislocation Z at positions 1, 2 and 3?
Assume all dislocations have identical Burgers vector.

Ques 38 GATE 2020

Which one of the following dislocation reactions is NOT feasible in a FCC crystal?

Ques 39 GATE 2020

X-ray diffraction pattern from an elemental metal with a FCC crystal structure shows the first peak at a Bragg angle θ = 24.65^o. The lattice parameter of this metal is _______ nm. Given, wavelength of the X-ray used is 0.1543 nm.