GATE MT topic:dislocation-theory PYQs & Answers

Questions 1–10 of 18. Imported answers require independent review unless marked reviewed.

Which one of the following options is correct? In a face-centered cubic metal, Shockley partial is:

Your answerChoose one option.

Perfect and mobile dislocation

Perfect and immobile dislocation

Imperfect and immobile dislocation

Imperfect and mobile dislocation

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 dislocation dissociation reactions is feasible in face-centered cubic metals?

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

The lattice parameter of Ni (face-centered cubic) is 0.35 nm and its shear modulus is 76 GPa. The strain energy per unit length of a screw dislocation in Ni crystal (rounded off to two decimal places) is ________ × 10⁻⁹ J/m.

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

With reference to edge and screw dislocations, which of the following statements is/are CORRECT?

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

Both edge and screw dislocations can leave the slip plane by climb.

Burgers vector of a screw dislocation is parallel to its line vector.

Both edge and screw dislocations can leave the slip plane by cross-slip.

Strain energy per unit length of an edge dislocation is higher than that of a screw dislocation.

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

A single crystal BCC metal with a lattice parameter

is subjected to deformation at a shear strain rate of

If the average mobile dislocation density in the single crystal is

, the average dislocation velocity is _____

(rounded off to two decimal places).

Given: Burgers vector

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

The figure shows a dislocation loop (shown by the solid circle), whose Burgers vector is

(shown by the horizontal arrow inside the dislocation loop). Identify the nature of the dislocation segment at locations p, q and r.

The dash-dot lines show the horizontal and vertical diameters of the loop, and the arrow along the dislocation loop indicates the line vector.

Diagram for Metallurgical Engineering question 24

Your answerChoose one option.

p: pure edge, q: mixed, r: pure screw

p: pure edge, q: pure screw, r: pure edge

p: pure screw, q: mixed, r: pure screw

p: pure screw, q: pure edge, r: pure screw

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

Match the concepts listed in Column I with the phenomena listed in Column II.

Your answerChoose one option.

P – 1, Q – 2, R – 3, S – 4

P – 4, Q – 1, R – 2, S – 3

P – 3, Q – 1, R – 2, S – 4

P – 3, Q – 4, R – 2, S – 1

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

Magnitude of Burgers vector of the dislocation resulting from reaction of dislocations with Burgers vectors

and

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

A dislocation loop PQRSTU is on the

plane of a cubic single crystal with Burgers vector

. The dislocation segments

and

are parallel to

and

directions, respectively.

Diagram for Metallurgical Engineering question 51

The correct statement(s) is/are

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

Dislocation segment PQ is mixed in character.

Dislocation segment UT is screw in character.

Dislocation segment PU is mixed in character.

Dislocation segment QR is edge in character.

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

Given the strain rate (

), dislocation density (

), dislocation velocity (

), which of the following relation(s) is(are) correct? Assume that Orowan equation for plastic flow due to the dislocation movement is obeyed.

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

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

GATE MT topic:dislocation-theory PYQs

How to practice topic:dislocation-theory

Question 16

Question 18

Question 52

Question 26

Question 61

Question 24

Question 25

Question 21

Question 51

Question 33