GATE XE purpose:exam-prep PYQs & Answers — Page 78

Questions 771–780 of 1772. Imported answers require independent review unless marked reviewed.

Which one of the following solvent environments will likely result in swell of solid polystyrene?

Your answerChoose one option.

0.1 M NaOH in H₂O

HCl (aq.) of pH = 6

Distilled water

Benzene

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Vickers microhardness (HV) of a ductile material A is higher than another ductile material B. Which of the following is/are true?

Your answerSelect all correct options. You can choose more than one.

Young’s modulus of A is greater than B

Yield strength of A is greater than B

Scratch resistance of A is greater than B

Ductility of A is greater than B

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

The enthalpy required to create an oxygen vacancy in CeO₂ is 4 eV. The number of oxygen vacancies present per mole of CeO₂ at 1000 K is ________. (Round off to the nearest integer)

Given:

: Avogadro’s number = 6.02×10²³ mole⁻¹

: Boltzmann’s constant = 8.62×10⁻⁵ eV/K

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

An electrochemical reaction is known to occur at +4.50 V against a Li⁺/Li reference electrode. The potential of the same reaction against a Zn²⁺/Zn reference electrode is ________ V. (Round off to two decimal places).

Given:

E⁰ (Li⁺/Li) = −3.04 V versus Standard Hydrogen Electrode

E⁰ (Zn²⁺/Zn) = −0.77 V versus Standard Hydrogen Electrode

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

For a binary system at constant pressure, there are two types of invariant reactions:

(i) α ↔ β + γ

(ii) α + β ↔ γ

Analogously, how many different types of invariant reactions may exist under variable temperature and pressure, for a binary system?

Your answerChoose one option.

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

For a glass marginally below its glass transition temperature, which one of the following statements is true?

Your answerChoose one option.

Glass has higher enthalpy than both the corresponding crystalline and liquid phases

Glass has lower enthalpy than both the corresponding crystalline and liquid phases

Glass has higher entropy than the corresponding crystalline phase and lower entropy than the corresponding liquid phase

Glass has lower entropy than the corresponding crystalline phase and higher entropy than the corresponding liquid phase

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Which one of the following samples of high-purity aluminium (Al) single crystal will plastically yield at the lowest applied load under ambient conditions? Loading axis is along the direction shown in the schematic.

Diagram for Engineering Sciences question 55

Your answerChoose one option.

(i)

(ii)

(iii)

(iv)

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Refer to the schematic shown. Two dog-bone samples, labeled 1 and 2, of a Cu-alloy are tested under tension at room temperature to points “E” and “P”, respectively. Subsequently, they are unloaded completely and metallographically polished. Brinell hardness testing was performed in the gauge section of the samples. Which one of the following can be inferred about the measured Brinell hardness number (BHN)?

Diagram for Engineering Sciences question 56

Your answerChoose one option.

BHN of 1 > BHN of 2

BHN of 1 = BHN of 2

BHN of 1 < BHN of 2

A conclusion about BHN of samples 1 and 2 cannot be made, with the provided information

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

During the ageing of a homogenized Al-Cu alloy (1 to 4 wt.% Cu) below the GP zone solvus, hardness of the alloy:

Your answerChoose one option.

increases monotonically

decreases monotonically

first increases and then decreases

first decreases and then increases

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

A student aims to deposit a thin metallic film on SiO₂ substrate, with an adhesion layer between the metal film and substrate, in a contiguous planar fashion. Island type of growth must be avoided. The student performs an extensive optimization exercise. Which one of the following steps is in the right direction?

Your answerChoose one option.

Choose a metallic adhesion layer with very low interfacial energy with the deposited thin film

Choose a metallic adhesion layer with very low interfacial energy with SiO₂, irrespective of its interaction with metal film to be deposited

Increase the substrate temperature and decrease the deposition rate

Use intermittent stages of deposition followed by annealing

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

GATE XE purpose:exam-prep PYQs

Question 49

Question 50

Question 51

Question 52

Question 53

Question 54

Question 55

Question 56

Question 57

Question 58