Chapter 1: Solid State

The total number of tetrahedral voids in the face-centred unit cell is __________.

(i) 6

(ii) 8

(iii) 10

(iv) 12

Which of the following point defects are shown by AgBr(s) crystals?

(A) Schottky defect (B) Frenkel defect

(C) Metal excess defect (D) Metal deficiency defect

In which pair most efficient packing is present?

The percentage of empty space in a body-centred cubic arrangement is

________.

(i) 74

(ii) 68

(iii) 32

(iv) 26

Solution;

Option (iii) is the answer.

Which of the following statement is not true about the hexagonal close

packing?

third layer.

those of the first layer.

In which of the following structures coordination number for cations and

anions in the packed structure will be the same?

of the unit cell.

What is the coordination number in a square close-packed structure in two

dimensions?

(i) 2

(ii) 3

(iii) 4

(iv) 6Solution:

Option (iii) is the answer.

Which kind of defects are introduced by doping?

Silicon doped with electron-rich impurity forms ________.

(i) p-type semiconductor

(ii) n-type semiconductor

(iii) intrinsic semiconductor

(iv) insulator

Which of the following statements is not true?

with respect to each other.

substances.