Quiz for Defects

Q1: Which type of defect increases the density of a solid?

A. Schottky defect B. Frenkel defect C. Interstitial defect D. Vacancy defect

Q2: What is created when NaCl crystal is heated in Na vapor?

A. Schottky defect B. Frenkel defect C. Metal excess defect D. Vacancy defect

Q3: Frenkel defect is most common in which compound?

A. KCl B. ZnS C. AgBr D. NaCl

Q4: Which defect lowers the density of a crystal?

A. Frenkel B. Interstitial C. Metal excess D. Schottky

Q5: In Schottky defect:

A. Only anions leave the lattice B. Both cation and anion leave the lattice C. Only cation leaves the lattice D. Interstitial atom is formed

Q6: Which defect does not affect density?

A. Frenkel defect B. Schottky defect C. Interstitial defect D. Substitution defect

Q7: AgCl shows both:

A. Schottky and Frenkel defects B. Frenkel and Interstitial defects C. Metal excess and Schottky D. Frenkel and Metal deficiency

Q8: Presence of an F-center gives:

A. Electrical conductivity B. Blue color C. Magnetic property D. Paramagnetism

Q9: Which defect is shown by ZnS?

A. Schottky B. Frenkel C. Interstitial D. Vacancy

Q10: What type of defect is introduced when a higher valence cation is doped?

A. Vacancy defect B. Frenkel defect C. Schottky defect D. Electronic defect

Q11: Which defect leads to color in crystals?

A. Frenkel B. Metal excess C. Schottky D. Vacancy

Q12: Vacancy defect leads to:

A. Increase in density B. No change in mass C. Decrease in density D. No change in volume

Q13: In metal deficiency defect, the cation is replaced by:

A. Anion B. Another cation of higher charge C. Electron D. Atom of same element

Q14: Color of KCl crystal changes in Na vapor due to:

A. Interstitial Na⁺ B. Vacancy defect C. F-centers D. Frenkel defect

Q15: F-centers are:

A. Electron holes B. Anion vacancies with electrons C. Cation defects D. Interstitial atoms

Q16: Which of the following is a non-stoichiometric defect?

A. Frenkel B. Schottky C. Metal excess D. Vacancy

Q17: Which defect creates paramagnetism?

A. Metal excess defect B. Schottky defect C. Frenkel defect D. Vacancy defect

Q18: Zinc oxide shows which defect on heating?

A. Metal deficiency B. Metal excess C. Schottky D. Interstitial

Q19: Which defect occurs in AgBr?

A. Schottky B. Frenkel C. Both A and B D. Metal deficiency

Q20: Which is true for Frenkel defect?

A. It increases density B. It does not affect density C. It increases volume D. It removes ions