Question

Question H 1Multiple Choice Questions) (10 Marks) 1. Figure out the odd statement about ceramics in the following (a) Good insulators of heat and electricity (b) Usually less desire than metals (c) Ductile in nature (d) Contains both metallic and nonmetallic elements 2. Major ingredients of traditional ceramics (a) silica (b) clay (c) feldspar (d) all 3. Not a characteristic property of ceramic material (a) high temperature stability (b) high mechanical strength (c) low elongation (d) low hardness 4. Give three differences between corrosion of metals and the corrosion of ceramics? What is static Fatigue? Ans: 5. Define Frenkel defect and Schottky defect? Ans:

Answer 1

1. C

Ceramics are brittle in nature so statement C is wrong.

2.D

All three are ingradients.

3. B

Ceramics have low mechanical strength.

4. Ceramics corrosion is rather a simple dissolution of material rather than an electrochemical reaction which occers in metal corrosion.

5. SCHOTTKY DEFECT: THIS DEFECT OCCURS IN NON IONIC LATTICE. IN THIS DEFECT SAME NO. OF CATIONS AND ANIONS LEAVE THEIR LATTICE SITE.

FRENKEL DEFECT: It is a type of defect in crystalline solids wherein an atom is displaced from its lattice position to an interstitial site, creating a vacancy at the original site and an interstitial defect at the new location within the same element without any changes in chemical properties.