Metallurgical Engineering Gate 2019 Questions with Answer

Ques 27 GATE 2019

During low strain rate (≤ 0.1 per second) deformation of a metal at room temperature, the one that deforms by twinning mode is _______.

Ques 28 GATE 2019

In a tensile creep test of a metal, Nabarro-Herring mechanism is favored over Coble mechanism for _______.

Ques 29 GATE 2019

Beach marks are commonly observed on the fractured surfaces of metals after a _______.

Ques 30 GATE 2019

The length of internal cracks in two samples of the same glass is measured to be c₁ = 0.5 mm and c₂ = 2 mm. The ratio (σ₁ / σ₂) of the fracture strength of the two samples is _______.

Ques 31 GATE 2019

The most suitable non-destructive testing method for detecting small internal flaws in a dense bulk material is _______.

Ques 32 GATE 2019

A FCC crystal with a lattice parameter of 0.3615 nm is used to measure the wavelength of monochromatic X-rays. The Bragg angle (θ) for the reflection from (111) planes is 21.68^o. The wavelength of X-rays (in nm, rounded off to three decimal places) is _______.

Ques 33 GATE 2019

The table (see options below) providing correct information about crystal structure, co-ordination number and packing fraction is _______. [Note: FCC: Face centered cubic; BCC: Body centered cubic; DC: Diamond cubic. CN: Coordination number; PF: Packing fraction]

A

B

C

D

Ques 34 GATE 2019

Match the phase transformation in Column I with the corresponding reaction in Column II. [Note: α, β, γ are solid phases; L, L₁, L₂ are liquid phases.]

Ques 35 GATE 2019

In a typical scanning electron microscope (SEM) image, information about topography and atomic contrast are obtained from _______.

Ques 36 GATE 2019

Match the ceramics in Column I with corresponding application in Column II.

Ques 37 GATE 2019

An aluminium single crystal is loaded in tension along axis. Among the following slip systems, the one that will be activated first is _______.
(A) (111)
(B) (111)
(C) (111)
(D) (111)

A

B

C

D

Ques 38 GATE 2019

A 50 mm (diameter) sphere of solid nickel is oxidized in a gas mixture containing 60% argon and 40% oxygen by volume. The rate of oxidation of nickel is controlled by the rate of transport of oxygen through the concentration boundary layer. The rate of oxidation (in moles of nickel per minute (mol / min), rounded off to two decimal places) is _______.
Given: Total pressure = 1 atm.; Temperature = 1173 K; Concentration of oxygen at the surface of the solid = 0; Boundary layer mass transfer coefficient = 0.03 m⋅s⁻¹; Universal gas constant, R = 8.205 × 10⁻⁵ m³⋅atm⋅K⁻¹⋅mol⁻¹; Assume ideal gas behavior.

Ques 39 GATE 2019

Cold working of iron leads to increase in dislocation density from 10¹⁰ to 10¹⁵ m⁻². The associated stored energy (in MJ⋅m⁻³, rounded off to one decimal place) is _______.
Given: Shear modulus of iron = 82 GPa; Burger's vector, b⃗ = a₀/2. a₀ = 0.2856 nm.