Question 1.

Glass is an amorphous solid can you convert it into a crystalline solid, name the process

 

Question 2.

What is forbidden gap, arrange all the band according to their energy gap.

 

Question 3.

The edge length of the unit cells in term of radius of spheres constituting fcc, bcc and simple cubic unit cell are respectively:

a.

Question4.

Chromium form cubic crystals whose unit cell has an edge length of 363pm volume of crystal is 7.22gml^-1 calculate the number of atoms per unit of chromium assuming that all lattice point. Also predict the type of crystal structure of chromium.

Question5.

What is edge dislocation and screw dislocation?

Question6.

An element ‘X’( atomic masss = 40g mol^-1) having fcc structure has unit cell edge length of 400pm. Calculate the density of X and the no. or unit cell in 4g of X.

Question7.

What do you understand by piezoelectricity and anti-piezoelectricity?

Question8.

Schottky defect in crystal observed when

(a) unequal no. of cation and anion is missing

(b) equal no. of cation and anion is missing

(c) anion leaves its normal site and occupies an intestinal site.

(d) ensity of crystal decreases.

Question9.

Which of the following compound is metallic and ferromagnetic?

(a) CrO₂

() VO₂

(c) MnO₂

(d) TiO₂

Question10.

The first order diffraction from the surface of the crystal is observed at an angle of Ѳ = 10.5⁰ with X- ray of wavelength 0.134nm. The distance between the planes of crystal is

(a) 1.32 nm

(b) 0.134 nm

(c) 9.73 nm

(d)11.3 nm

Question11.

The radius ratio r/R ≥ 0.414 corresponds to which one of the following voids

(a) trigonal

(b) tetragonal

(c) octahedral

(d) BCC

Question12.

Aluminium has a body centered cubic structure. The length of unit cell is 256pm, its density is 19.3gcm^-3 and the molar mass of Al is 27 gmol^-1 calculate Avogadro no.

Question13.

In a cubic unit cell, seven of the eight corner are occupied by Atom A and centred of the Faces are occupied by Atom B. The general Formula of the compound is

(a) A₇B₆

(b) A₂₄B₇

_{(c) A7B12}

_{(d) A7B24}

Question14.

In seven possible crystals how many crystals system have α = β

(a) 5

(b) 3

(c) 2

(d) 4

Question16.

Which statement is correct?

(a) When temperature increases then number of defect decreases.

(b) Schottky defect occurs when radius of cation is smaller.

(c) Frenkel defect occurs when radius of cation is smaller.

(d) None of these

Question17.

Examine the statement carefully and mark the correct answer according to instruction.

A if both statements are true and statement 2 is the correct answer of statement 1,

B If both statements are true but statement 2 is not the correct answer of statement 1.

C statement 1 is true and statement 2 is false.

D statement 1 is false but statement 2 is true.

Statement 1 – Antiferromagnetic substance become paramagnetic on heating to high

temperature.

Statement 2 – Heating result in spins of electron becoming random.

Question18.

In planer tetra-atomic molecule, XY₃, X is at the centroid of the equilateral triangle formed by the atoms, Y if the X -Y bond distance is 1 A⁰, what is the distance between the centre of any two Y atoms?

(a) 1/√3

(b)√2 A⁰

(c)√3 A⁰

(d)1/√2 A⁰

Question19.

Why amorphous solid is called pseudo solid and crystalline is true. Explain?

Question20.

Match the following:

 

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