Crystal defects or imperfections | Crystal physics | தமிழில் | Anusuya A скачать в хорошем качестве

Crystal defects or imperfections | Crystal physics | தமிழில் | Anusuya A

Crystal defects or imperfections | Crystal physics | தமிழில் | Anusuya A Crystal defects oneword(mcqs) | Anusuya A 1. Which of the following is a point defect in crystals? a) Edge dislocation b) Interstitialcies c) Grain boundaries d) Cracks Answer: b Explanation: Crystal defects are classified as point defects, line defects, and boundary defects. Point defects include vacancies, impurities, interstitialcies, and electronic defects. 2. The defect that occurs due to a displacement of an ion is known as __________ a) Vacancy defect b) Schottky defect c) Frankel defect d) Interstitial defect Answer: c Explanation: Frankel defect occurs due to a displacement of an ion from the crystal lattice. It is related to the interstitial defect, where an ion simply occupies a position between regular atoms. 3._______ occurs when a foreign substance replaces an atom in a crystal. a) Vacancy defect b) Substitutional impurity c) Frankel defect d) Interstitial impurity Answer: b Explanation: A substitutional impurity occurs due to the occupation of a foreign atom in place of an atom in a crystal. On the other hand, interstitial impurities occur when a regular atom occupies a random space in the crystal lattice. 4.A disturbance in a region between two ideal parts of a crystal is known as ________ a) Boundary defect b) Point defect c) Line defect d) Volume defect Answer: c Explanation: Line defect is regarded as a disturbed region between two perfect parts of a crystal. They may be of either edge dislocation type or screw dislocation. 5. In screw dislocation, the Burger’s vector lies _________ to the dislocation line. a) Perpendicular b) Parallel c) At an angle d) Sideways Answer: b Explanation: The Burger’s vector in screw dislocation lies parallel to the dislocation line along the axis of a line of atoms in the same plane. On the other hand, it lies at an angle for edge dislocation. 6.  What are one-dimensional defects? a) Boundary defect b) Point defect c) Line defect d) Volume defect Answer: c Explanation: When compared geometrically, line defects are seen as one-dimensional defects. Line defects are also known as dislocations, with common types as edge and screw dislocations. 7.What are two-dimensional defects? a) Boundary defect b) Point defect c) Line defect d) Volume defect Answer: a Explanation: The defects that occur on the surface of a material are known as surface or boundary defects. Geometrically, they are regarded as two-dimensional defects.