Physics Group - II (3110018) MCQs

MCQs of Electronic Materials

Showing 11 to 20 out of 23 Questions
11.

The expression for the effective mass is derived as

(a)

m*=2d2Ed k2

 
(b)

m*=d2Ed k2

 
(c)

m*=-2d2Ed k2

(d)

none

Answer:

Option (a)

12.

Drude-Lorentz theory is

(a)

Classical free electron theory

(b)

Quantum free electron theory

(c)

Band theory

(d)

none

Answer:

Option (a)

13.

Classical free electron theory of metals assumes

(a)

Free electron gas

(b)

Thermal motion of free electrons

(c)

Drift motion of free electrons

(d)

All

Answer:

Option (d)

14.

The quantized value of energy is given by

(a)

E=h28mL2(nx2+ny2+nz2)

(b)

n=(nx2+ny2+nz2)

(c)

n=18×4π3n3

(d)

None

Answer:

Option (a)

15.

Quantum free electron theory was developed by 

(a)

Drude

(b)

Lorentz

(c)

Somerfield

(d)

None

Answer:

Option (c)

16.

Quantum free electron theory assumes electrons are charged particles and obey.................principal.

(a)

Pauli Exclusive

(b)

Hund's 

(c)

aufbau

(d)

None

Answer:

Option (a)

17.

The cause for electrical resistance of a metal is

(a)

impurities and crystal defects

(b)

thermal vibration

(c)

non - periodicity of lattice potentials

(d)

all of above

Answer:

Option (d)

18.

Quantum free electron theory of metals successfully explains

(a)

electrical conductivity

(b)

specific heat and thermionic emission

(c)

paramagnetism

(d)

all

Answer:

Option (d)

19.

Quantum free electron theory of metals fails to explain

(a)

the difference between conductors, semiconductors, and insulators

(b)

positive Hall coefficient of metals

(c)

lower conductivities of divalent metals than monovalent metals

(d)

all

Answer:

Option (d)

20.

Kroning - Penney model is

(a)

approximate model

(b)

real model

(c)

both a and b

(d)

none

Answer:

Option (a)

Showing 11 to 20 out of 23 Questions