Question 1

A metal is a good conductor because the valence energy band for electrons is

Accepted Answer

A)  empty.
B)  completely full.
C)  full,but there is only a small gap to a higher empty band.
D)  partly full.
E)  None of these is correct.F) A) and B)
G) All of the above

Question 2

Use the following to answer the question:

-The Fermi energy in three dimensions at T = 0 is given by  The Fermi energy for aluminum is approximately

Accepted Answer

A)  11.7 eV
B)  3.24 eV
C)  5.53 eV
D)  2.11 eV
E)  9.46 eVF) A) and C)
G) A) and B)

Question 3

In the classical free-electron theory of metals,

Accepted Answer

A)  a metal is pictured as a regular three-dimensional array of atoms or ions.
B)  a metal contains a large number of electrons that are free to move throughout the whole metal.
C)  thermal equilibrium is maintained by collisions of electrons with the lattice ions.
D)  electrons in the absence of an electric field move about the metal much as gas molecules move in a container.
E)  All of these are true.F) B) and D)
G) C) and E)

Question 4

The classical theory of conduction

Accepted Answer

A)  fails because electrons are not classical particles.
B)  does not take into account the scattering of electron waves by a lattice.
C)  fails to correctly describe the collision of an electron with a lattice ion.
D)  predicts a Maxwell-Boltzmann-like distribution of electron velocities.
E)  is described by all of these.F) B) and C)
G) None of the above

Question 5

The average energy of a Fermi electron gas at T = 0 is

Accepted Answer

A)  3kT/2
B)  EF 
C)  kT
D)  zero
E)  3EF/5F) B) and C)
G) All of the above

Question 6

The crystalline structure known as hexagonal close-packed

Accepted Answer

A)  is characterized by the stacking of identical spheres.
B)  occurs when every ion has eight nearest-neighbor ions of opposite charge.
C)  corresponds to an alternating pattern of ions.
D)  occurs when an ion of either kind has six nearest neighbors of the other kind.
E)  None of these is correct.F) All of the above
G) B) and D)

Question 7

Use the following to answer the question. 
-The graph that represents the Fermi factor F is

Accepted Answer

A)  1
B)  2
C)  3
D)  4
E)  5F) A) and B)
G) A) and C)

Question 8

If you want to produce an amorphous solid from a liquid,you

Accepted Answer

A)  cool the liquid slowly so that the molecules gradually lose their kinetic energy and thus form a maximum number of bonds.
B)  cool the liquid rapidly to remove its internal energy before the molecules have a chance to form many bonds.
C)  maintain the temperature of the liquid while increasing the pressure applied to the liquid.
D)  maintain the temperature of the liquid while decreasing the pressure applied to the liquid.
E)  warm the liquid while decreasing its pressure.F) A) and B)
G) C) and D)

Question 9

The frequency of the current observed at a Josephson junction is 345 MHz.The voltage applied to the junction to produce this current was

Accepted Answer

A)  1.43 µV
B)  1.43 V
C)  0.715 µV
D)  0.715 mV
E)  1.28 µVF) B) and D)
G) A) and E)

Question 10

A semiconductor for which it is true that the major charge carriers are holes

Accepted Answer

A)  is called an n-type semiconductor.
B)  is called a p-type semiconductor.
C)  accepts positive charges from filled valence bands.
D)  is devoid of acceptor levels.
E)  None of these is correct.F) All of the above
G) A) and B)

Question 11

The classical free-electron theory of metals

Accepted Answer

A)  correctly predicts the resistivity of a conductor but fails to predict the correct temperature dependence of the resistivity.
B)  correctly predicts both the resistivity of a conductor and its temperature dependence.
C)  incorrectly predicts the resistivity of a conductor but correctly predicts its temperature dependence.
D)  incorrectly predicts both the resistivity of a conductor and its temperature dependence.
E)  correctly predicts which materials are conductors,insulators,or semiconductors.F) A) and D)
G) C) and D)

Question 12

Which of the following statements is false?

Accepted Answer

A)  The behavior of free electrons in a metal is very different from the behavior of the molecules in an ordinary gas.
B)  Ordinary gas molecules are described by the classical Maxwell-Boltzmann energy distribution function.
C)  The main features of a Fermi electron gas can be understood by assuming an electron in a metal to be a particle in a box.
D)  No two electrons in an atom can be in the same quantum state.
E)  None of these is false.F) C) and E)
G) A) and B)

Question 13

Molecules in a liquid

Accepted Answer

A)  have little influence on one another.
B)  have little influence on one another except during their frequent but brief collisions.
C)  are close together and exert forces on one another that are comparable to the forces that bind atoms into molecules.
D)  form temporary short-range bonds that continually break and re-form due to the thermal kinetic energy of the molecules.
E)  are always arranged in a crystalline structure.F) A) and B)
G) A) and E)

Question 14

If the energy levels of a Fermi gas is given by En = nE1,the total energy of seven fermions in the ground state is

Accepted Answer

A)  7E1
B)  9E1
C)  11E1
D)  14E1
E)  16E1F) C) and D)
G) B) and E)

Question 15

Use the following to answer the question below:

-The probability that an energy state in magnesium 0.05 eV below the Fermi energy is occupied at T = 300 K is

Accepted Answer

A)  5.52%
B)  20.6%
C)  47.1%
D)  87.4%
E)  99.9%F) A) and B)
G) B) and D)

Question 16

The crystalline structure known as face-centered-cubic

Accepted Answer

A)  is characterized by the stacking of identical spheres.
B)  occurs when every ion has eight nearest-neighbor ions of opposite charge.
C)  corresponds to an alternating pattern of ions.
D)  occurs when an ion of either kind has six nearest neighbors of the other kind.
E)  None of these is correct.F) A) and E)
G) All of the above

Question 17

According to the BCS theory,

Accepted Answer

A)  electrons in a superconductor are coupled in pairs at low temperatures.
B)  electrons in a Cooper pair have equal and opposite spins.
C)  electrons in a Cooper pair act as a single particle with zero spin.
D)  any number of Cooper pairs may be in the same quantum state with the same energy.
E)  All of these are true.F) B) and C)
G) A) and E)

Question 18

Use the following to answer the question below: 
F for magnesium is A) 1.42  	imes  106 m/s B) 1.84  	imes  106 m/s C) 1.21  	imes  106 m/s D) 2.03  	imes  106 m/s E) 1.58  	imes  106 m/s " class="answers-bank-image d-inline" rel="preload" >
-The speed of a conduction electron whose energy is equal to the Fermi energy EF for magnesium is

Accepted Answer

A)  1.42  ×	imes×  106 m/s
B)  1.84  ×	imes×  106 m/s
C)  1.21  ×	imes×  106 m/s
D)  2.03  ×	imes×  106 m/s
E)  1.58  ×	imes×  106 m/s F) D) and E)
G) None of the above

Question 19

The crystal structure of a substance can be determined using X-ray diffraction.It can also be determined using neutron scattering.What is the kinetic energy of a neutron that has a wavelength of 0.1 nm?

Accepted Answer

A)  0.14 eV
B)  0.082 eV
C)  0.034 eV
D)  0.23 eV
E)  0.38 eV F) A) and B)
G) A) and E)

Question 20

The resistivity of iron at 20ºC is 10  ×	imes×  10-8  Ω\OmegaΩ  · m and the number of electrons per cubic centimeter is 17.0  ×	imes×  1022.If you take the average speed of the electrons to be equal to their root-mean-square speed (at T = 300 K) of 1.17  ×	imes×  105 m/s,it follows that their mean free path, λ\lambdaλ  ,must be

Accepted Answer

A)  0.245 nm
B)  0.317 nm
C)  0.428 nm
D)  0.556 nm
E)  None of these is correct. F) C) and D)
G) C) and E)

Exam 38: Solids and the Theory of Conduction

The frequency of the current observed at a Josephson junction is 345 MHz.The voltage applied to the junction to produce this current was

Correct Answer
verified

In the classical free-electron theory of metals,

Correct Answer
verified

A semiconductor for which it is true that the major charge carriers are holes

Correct Answer
verified

The crystalline structure known as hexagonal close-packed

Correct Answer
verified

The crystalline structure known as face-centered-cubic

Correct Answer
verified

Use the following to answer the question: -The Fermi energy in three dimensions at T = 0 is given by The Fermi energy for aluminum is approximately

Correct Answer
verified

The average energy of a Fermi electron gas at T = 0 is

Correct Answer
verified

If the energy levels of a Fermi gas is given by E_n = nE₁,the total energy of seven fermions in the ground state is

Correct Answer
verified

Correct Answer
verified

Use the following to answer the question. -The graph that represents the Fermi factor F is

Correct Answer
verified

A metal is a good conductor because the valence energy band for electrons is

Correct Answer
verified

The classical theory of conduction

Correct Answer
verified

The classical free-electron theory of metals

Correct Answer
verified

According to the BCS theory,

Correct Answer
verified

Correct Answer
verified

Which of the following statements is false?

Correct Answer
verified

Use the following to answer the question below: -The probability that an energy state in magnesium 0.05 eV below the Fermi energy is occupied at T = 300 K is

Correct Answer
verified

Molecules in a liquid

Correct Answer
verified

If you want to produce an amorphous solid from a liquid,you

Correct Answer
verified

The crystal structure of a substance can be determined using X-ray diffraction.It can also be determined using neutron scattering.What is the kinetic energy of a neutron that has a wavelength of 0.1 nm?

Correct Answer
verified

Exam 38: Solids and the Theory of Conduction

The frequency of the current observed at a Josephson junction is 345 MHz.The voltage applied to the junction to produce this current was

Correct AnswerverifiedShow Answer

In the classical free-electron theory of metals,

Correct AnswerverifiedShow Answer

A semiconductor for which it is true that the major charge carriers are holes

Correct AnswerverifiedShow Answer

The crystalline structure known as hexagonal close-packed

Correct AnswerverifiedShow Answer

The crystalline structure known as face-centered-cubic

Correct AnswerverifiedShow Answer

Use the following to answer the question: -The Fermi energy in three dimensions at T = 0 is given by The Fermi energy for aluminum is approximately

Correct AnswerverifiedShow Answer

The average energy of a Fermi electron gas at T = 0 is

Correct AnswerverifiedShow Answer

If the energy levels of a Fermi gas is given by En = nE1,the total energy of seven fermions in the ground state is

Correct AnswerverifiedShow Answer

Use the following to answer the question below: -The speed of a conduction electron whose energy is equal to the Fermi energy EF for magnesium is

Correct AnswerverifiedShow Answer

Use the following to answer the question. -The graph that represents the Fermi factor F is

Correct AnswerverifiedShow Answer

A metal is a good conductor because the valence energy band for electrons is

Correct AnswerverifiedShow Answer

The classical theory of conduction

Correct AnswerverifiedShow Answer

The classical free-electron theory of metals

Correct AnswerverifiedShow Answer

According to the BCS theory,

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Which of the following statements is false?

Correct AnswerverifiedShow Answer

Use the following to answer the question below: -The probability that an energy state in magnesium 0.05 eV below the Fermi energy is occupied at T = 300 K is

Correct AnswerverifiedShow Answer

Molecules in a liquid

Correct AnswerverifiedShow Answer

If you want to produce an amorphous solid from a liquid,you

Correct AnswerverifiedShow Answer

The crystal structure of a substance can be determined using X-ray diffraction.It can also be determined using neutron scattering.What is the kinetic energy of a neutron that has a wavelength of 0.1 nm?

Correct AnswerverifiedShow Answer

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verified

Correct Answer
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If the energy levels of a Fermi gas is given by E_n = nE₁,the total energy of seven fermions in the ground state is

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
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Correct Answer
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