Top 1000+ Solved Material Science MCQ Questions Answer
Q. On thermal excitation this defect may cause
a. vacancy
b. edge dislocations
c. screw dislocations
d. none of the above
Q. The grain boundary area decreases when a polycrystalline material is heated
a. below recrystalliza tion temp.
b. above recrystalliza tion temp.
c. above room temp.
d. below 0.5 tm
Q. The imperfections may be minimised by
a. thermal energy
b. making metal in fibre form
c. surface treatment
d. all of the above
Q. The cross slip occurs in :
a. climb up motion
b. screw dislocation
c. gliding motion
d. none of the above
Q. .......... defects are inperfect point like region in a crystal.
a. line
b. point
c. edge
d. screw
Q. A ............is the simplest point defect and envolves a missing atom within a metal.
a. schottky
b. vacancy
c. line
d. dislocation
Q. -------- imperfections involve vacancies of a pair ions of opposite charges.
a. frankel
b. schottky
c. dislocation
d. point
Q. The displacement distance for atoms around the dislocation is the---- --.
a. burger vector
b. screw
c. edge
d. point
Q. -------- are difined as the irregularities in the structure of metals.
a. atomic
b. dislocation
c. point
d. vacancies
Q. Surface defects are the -------- dimensional regions in a crystal.
a. three
b. two
c. four
d. one
Q. -------- dislocation plays an important role in crystal growth.
a. edge
b. screw
c. vacancies
d. schotty