(1) Frenkel defect is usually favoured by a very small difference in sizes of cation and anion

(2) Frenkel defect is a dislocation defect

(3) Trapping of an electron in the lattice leads to formation of F-Center

(4) Schottky defects have no effect on physical properties of solids

$\begin{array}{1 1} (1)\;and\;(2) \\ (2)\;and\;(3) \\ (3)\;and\;(4) \\ (2)\;and\;(4) \end{array}$