Which type of defect is observed in $AgBr$?

Select the incorrect statement for Schottky defect.

Non-stoichiometric defects do not include which of the following?

The correct statement regarding defects in solids is

Which of the following crystals exhibits both Schottky and Frenkel defects?

Metal deficiency defect is shown by $Fe_{0.93}O$. In the crystal,some $Fe^{2+}$ cations are missing and loss of positive charge is compensated by the presence of $Fe^{3+}$ ions. The percentage of $Fe^{2+}$ ions in the $Fe_{0.93}O$ crystals is $....$ (Nearest integer)