Free Printable Solid State Physics-II

1.

According to Drude

a)

the valence electrons of atoms move freely like gas molecules in a solid

b)

the valence electrons of atoms move under coulomb field of atoms but they themselves do not apply any force on each other and like gas molecules in a solid

c)

the valence electrons of atoms move under coulomb field of atoms

d)

all electrons move freely in side solid

2.

Drift velocity expression is $vd=\ \frac{e\tau}{m}$ , current density is $J=nevd$ then using Ohms law $J=\sigma E$ ; $\sigma\ \exp ression\ is$

a)

$\frac{ne\tau}{m}$

b)

$\frac{ne2\tau}{m}$

c)

$\frac{\eta e}{m}$

d)

$\frac{m}{ne2\tau}$

3.

Drude's model is good enough to explain

a)

Ohm's law and Widemann Franz law

b)

Ohm's law and conduction in semiconductor

c)

Ohm's law and Jule's law

d)

Ohm's law anFaraday's law

4.

Wiedemann Franz law

a)

$K\ =L\sigma T$

b)

$\frac{K}{T}=L$

c)

$\frac{K}{T}=\sigma$

d)

$K\sigma=T$

5.

Differences of Drude's model and Somerfeld free electron theory is

a)

Drude used particle picture and Somerfeld used wave picture

b)

Drude used wave picture and Somerfeld used particle picture

c)

Drude used only electronic case and Somerfeld considered both electron and hole

d)

Drude used both for electron and hole and Somerfeld used only for electron

6.

Somerfeld's free electron theory is equivalent to

a)

3D box problem of Q.Mechanics

b)

1D infinite potential well problem

c)

1D finite potential well problem

d)

1D finite barrier well problem

7.

Energy of an electron accordingly to Somerfeld's free electron theory is

a)

$\frac{3}{2}KT$

b)

$\frac{n2\pi2h2}{2\pi m2}$

c)

$\frac{n\pi h}{2ma2}$

d)

$\frac{n2\pi2h}{2\pi m2}$

8.

a)

this picture represents electrons in infinite periodic potential

b)

this picture represents electrons in a finite potential well

c)

this picture represents electrons in a finite periodic potential well

d)

this picture represents electrons in a infinite potential well

9.

According to band theory

a)

electrons are moving freely without any interaction btn. themselves or atomic nuclei

b)

electrons are moving freely without any interaction btn. themselves but under Coulomb field of atomic nuclei

c)

electrons are moving freely between Coulomb interaction btn. themselves but under Coulomb field of atomic nuclei

d)

electrons are moving freely between mechanical interaction btn. themselves but under Coulomb field of atomic nuclei

10.

Band theory is explained using

a)

Newtonian eqn

b)

Schrodinger equation for 1D infinite pot. well prob

c)

Schrodinger equation with Kronig Penny model with Bloch funciton

d)

Schrodinger equation with Somerfeld model

11.

The\ relation\ \ \ \ P\frac{Sin\alpha a}{\alpha a}+Cos\alpha a\ =\ CosKa

illustrates that

a)

K values between $-\frac{\pi}{a\ }\ to\ \ +\frac{\pi}{a}$

b)

k values between $-\pi\ to\ \pi$

c)

k values between $-\frac{a}{\pi}\ to\ +\ \frac{a}{\pi}$

d)

k values between $-\frac{\pi}{2a}\ to\ +\frac{\pi}{2a}$

12.

The relation $K2=\frac{2mE}{\left(\frac{h}{2\pi}\right)2}$ and $K=-\frac{\pi}{a}\ to\ +\frac{\pi}{a}$ indicates

a)

E values allowed for K multiple of $-\frac{\pi}{a}\ to\ +\frac{\pi}{a}$

b)

E values allowed for K multiple of $-2\pi\ \ to\ +2\pi$

c)

E values allowed for K multiple of $-a\ to\ +a$

d)

E values allowed for K multiple of $-n\pi\ to\ +n\pi$

13.

Choose the Brillounin Zone

a)

b)

c)

14.

Density of states is defined as number of energy states per unit energy range i.e. dN/dE, so which one is the correct picture for this

a)

b)

c)

d)

15.

correct figure to represent Dos is

a)

b)

c)

d)

Solid State Physics-II

Total questions: 15

Worksheet time: 8mins

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