WorksheetsUNIT I FREE ELECTRON THEORY, CFET, QFET, EF, DOS
Total questions: 20
Worksheet time: 20mins
In solids, _________in outer most orbits of atoms determine its electrical properties
protons
neutron
electrons
positron
Free electron theory has been developed in ----------- main stages
1
2
3
5
This theory was developed by Drude & Lorentz in 1900
Classical free electron theory
Quantum free electron theory
Zone theory
Bloch theory
Sommerfield developed the quantum free electron theory in
1956
1900
1927
1928
According to this theory, free electrons move in a periodic potential provided by the lattice
Classical free electron theory
Quantum free electron theory
free electron theory
zone theory
In CFET, free electrons move in
unidirection
bidirection
random direction
one path
There is no loss of energy and resultant velocity is zero, this indicates ______ of free electrons
inelastic collision
elastic collision
Direct compact
Oblique impact
When an electric field is applied to the metal, the free electrons move in (a) direction
Pick out the odd one.
fails to explain the specific heat capacity of metals
explains new phenomena like photoelectric effect, Compton effect, black – body radiation
Susceptibility has greater theoretical value than the experimental value
fails to explain superconducting properties of metals
In QFET, Energy levels are
discrete
continuous
discontinuous
has increasing value
QFET follows
Maxwell-Boltzmann distribution
Bose-Einstein distribution
Fermi-Dirac distribution
Einstein-Kalam distribution
Wolfgang Pauli formulated the law stating that ____ electrons can have the same set of quantum numbers.
no two
only two
only one
no one
Highest energy level that can be occupied by an electron at 0 K
Excited state
Conduction state
Fermi energy
Average energy
Electron occupying an energy level can be determined by
probability function F(E)
probability function Z(E)
Normalized function F(E)
Occupation function N(E)
If F(E) =1, then
0% probability that the electrons to occupy energy level below Fermi level
50% probability that the electrons to occupy energy level below Fermi level
75% probability that the electrons to occupy energy level below Fermi level
100% probability that the electrons to occupy energy level below Fermi level
The ability of metal to conduct electricity depends upon
Energy state and Energy level
Micro state and Energy level
Energy state and Macrostate
quantum states alone
In density of states, the shape of metal piece considered initially was
sphere
shell
cube
cylinder
In DOS, volume of the sphere of radius n is equal to the number of energy states
volume of cube
number of energy states
number of energy levels
none in the list
O𝐧𝐥𝐲 𝐭𝐰𝐨 𝐞𝐥𝐞𝐜𝐭𝐫𝐨𝐧𝐬 𝐨𝐟 𝐨𝐩𝐩𝐨𝐬𝐢𝐭𝐞 𝐬𝐩𝐢𝐧 𝐜𝐚𝐧 𝐨𝐜𝐜𝐮𝐩𝐲 𝐞𝐚𝐜𝐡 𝐬𝐭𝐚𝐭𝐞. This was coined by
Neils Bohr
Drude
Wolfgang Pauli
Lorentz
Carrier concentration in metals is
ZE x FE
Z(E) x F(E) dE
N(E)dE x F(E) dE
Z(E)dE
