Question 1

Use the following to answer the question below: 
 
-At what energy is the Fermi factor equal to 0.2 for copper at T = 300 K?

Accepted Answer

A) 7.08 eV 
B) 7.00 eV 
C) 7.06 eV 
D) 7.02 eV 
E) 7.18 eV 
A) 7.08 eV 
B) 7.00 eV 
C) 7.06 eV 
D) 7.02 eV 
E) 7.18 eV

Question 2

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

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. 
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.

Question 3

If you apply a voltage of 0.3 µV to a Josephson junction,you can expect to measure a frequency of approximately

Accepted Answer

A) 327 MHz 
B) 484 Hz 
C) 145 kHz 
D) 484 MHz 
E) 145 MHz 
A) 327 MHz 
B) 484 Hz 
C) 145 kHz 
D) 484 MHz 
E) 145 MHz

Question 4

Metallic compounds have been found to exhibit superconductivity at temperatures as high as

Accepted Answer

A) 273 K 
B) 164 K 
C) 176 K 
D) 188 K 
E) 243 K 
A) 273 K 
B) 164 K 
C) 176 K 
D) 188 K 
E) 243 K

Question 5

A Josephson junction consists of

Accepted Answer

A) two superconductors separated by a thin insulating barrier. 
B) a superconductor sandwiched between two insulating barriers. 
C) two different superconductors in contact with each other. 
D) a superconductor in contact with a conductor warmer than 4.2 K. 
E) None of these is correct. 
A) two superconductors separated by a thin insulating barrier. 
B) a superconductor sandwiched between two insulating barriers. 
C) two different superconductors in contact with each other. 
D) a superconductor in contact with a conductor warmer than 4.2 K. 
E) None of these is correct.

Question 6

One of the principal advantages of the transistor over the thermionic triode as a circuit element is that the transistor

Accepted Answer

A) is a linear element. 
B) does not require a B battery. 
C) does not require power to heat a filament. 
D) has only two connections. 
E) can be made from ordinary resistor materials. 
A) is a linear element. 
B) does not require a B battery. 
C) does not require power to heat a filament. 
D) has only two connections. 
E) can be made from ordinary resistor materials.

Question 7

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

Accepted Answer

A) 1.57 $\times$ 106 m/s 
B) 1.84 $\times$ 106 m/s 
C) 1.21 $\times$ 106 m/s 
D) 2.03 $\times$ 106 m/s 
E) 3.14 $\times$ 106 m/s 
A) 1.57 $\times$ 106 m/s 
B) 1.84 $\times$ 106 m/s 
C) 1.21 $\times$ 106 m/s 
D) 2.03 $\times$ 106 m/s 
E) 3.14 $\times$ 106 m/s

Question 8

When light strikes the p-type semiconductor in a pn junction solar cell,

Accepted Answer

A) only free electrons are created. 
B) only positive holes are created. 
C) both electrons and holes are created. 
D) positive protons are created. 
E) None of these is correct. 
A) only free electrons are created. 
B) only positive holes are created. 
C) both electrons and holes are created. 
D) positive protons are created. 
E) None of these is correct.

Question 9

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

Accepted Answer

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

Question 10

Insulated electrical wires often have a maximum voltage rating,i.e.,the insulation on the wire is safe up to the rated voltage.The reason why the insulator is not safe at higher voltage is because

Accepted Answer

A) there is a possibility of electric breakdown,which will cause electrons in the valence band of the insulator to be promoted to the conduction band making the insulator a conductor. 
B) the wire will then carry more current,making the wire unsafe. 
C) most households only have 240 V maximum so there is no point having a higher voltage rating. 
D) it is the manufacturer's way of preventing users from transmitting higher voltage. 
E) None of these is correct. 
A) there is a possibility of electric breakdown,which will cause electrons in the valence band of the insulator to be promoted to the conduction band making the insulator a conductor. 
B) the wire will then carry more current,making the wire unsafe. 
C) most households only have 240 V maximum so there is no point having a higher voltage rating. 
D) it is the manufacturer's way of preventing users from transmitting higher voltage. 
E) None of these is correct.

Question 11

The resistivity of nichrome at 20ºC is 100 $\times$ 10-8 $\Omega$ · m.You have nichrome wire whose diameter is 2.50 mm and need a resistance of 100 $\Omega$.How long would a piece of this wire need to be to provide this resistance?

Accepted Answer

A) 196 m 
B) 491 m 
C) 543 m 
D) 867 m 
E) 1.96 km 
A) 196 m 
B) 491 m 
C) 543 m 
D) 867 m 
E) 1.96 km

Question 12

Use the following to answer the question below: 
 
-The probability that an energy state in magnesium 0.2 eV below the Fermi energy is occupied at T = 300 K is

Accepted Answer

A) 5.52% 
B) 20.6% 
C) 47.1% 
D) 83.9% 
E) 99.9% 
A) 5.52% 
B) 20.6% 
C) 47.1% 
D) 83.9% 
E) 99.9%

Question 13

If the atoms are treated as solid spheres,the fraction of volume occupied by the atoms in a body-centered-cubic unit cell is

Accepted Answer

A) 0.45 
B) 0.52 
C) 0.65  
D) 0.68 
E) 0.74  
A) 0.45 
B) 0.52 
C) 0.65  
D) 0.68 
E) 0.74

Question 14

When a pnp junction transistor is used as an amplifier,a small signal in the _____ current results in a large signal in the _____ current.

Accepted Answer

A) collector; base 
B) base; collector 
C) emitter; base 
D) emitter; collector 
A) collector; base 
B) base; collector 
C) emitter; base 
D) emitter; collector

Question 15

Copper has a mass density of 8.93 g/cm3 and its molar mass is 63.55 g.If each copper atom contributes one free electron,the carrier density is

Accepted Answer

A) 8.46 $\times$ 1028 m-3 
B) 3.12 $\times$ 1028 m-3 
C) 4.15 $\times$ 1028 m-3 
D) 6.48 $\times$ 1028 m-3 
E) None of these is correct. 
A) 8.46 $\times$ 1028 m-3 
B) 3.12 $\times$ 1028 m-3 
C) 4.15 $\times$ 1028 m-3 
D) 6.48 $\times$ 1028 m-3 
E) None of these is correct.

Exam 38: Solids and the Theory of Conduction

Use the following to answer the question below: -At what energy is the Fermi factor equal to 0.2 for copper at T = 300 K?

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

If you apply a voltage of 0.3 µV to a Josephson junction,you can expect to measure a frequency of approximately

Metallic compounds have been found to exhibit superconductivity at temperatures as high as

A Josephson junction consists of

One of the principal advantages of the transistor over the thermionic triode as a circuit element is that the transistor

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

When light strikes the p-type semiconductor in a pn junction solar cell,

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

Insulated electrical wires often have a maximum voltage rating,i.e.,the insulation on the wire is safe up to the rated voltage.The reason why the insulator is not safe at higher voltage is because

The resistivity of nichrome at 20ºC is 100 ×\times× 10-8 Ω\OmegaΩ · m.You have nichrome wire whose diameter is 2.50 mm and need a resistance of 100 Ω\OmegaΩ .How long would a piece of this wire need to be to provide this resistance?

Use the following to answer the question below: -The probability that an energy state in magnesium 0.2 eV below the Fermi energy is occupied at T = 300 K is

If the atoms are treated as solid spheres,the fraction of volume occupied by the atoms in a body-centered-cubic unit cell is

When a pnp junction transistor is used as an amplifier,a small signal in the _____ current results in a large signal in the _____ current.

Copper has a mass density of 8.93 g/cm3 and its molar mass is 63.55 g.If each copper atom contributes one free electron,the carrier density is

Systems of Measurement

Motion in One Dimension

Motion in Two and Three Dimensions

Newtons Laws

Applications of Newtons Laws

Work and Energy

Conservation of Energy

Systems of Particles and Conservation of Linear Momentum

Rotation

Conservation of Angular Momentum

Gravity

Static Equilibrium and Elasticity

Fluids

Oscillations

Wave Motion

Superposition and Standing Waves

Temperature and the Kinetic Theory of Gases

Heat and the First Law of Thermodynamics

The Second Law of Thermodynamics

Thermal Properties and Processes

The Electric Field I: Discrete Charge Distributions

The Electric Field Ii: Continuous Charge Distributions

Electric Potential

Capacitance

Electric Current and Direct-Current Circuits

The Magnetic Field

Sources of the Magnetic Field

Magnetic Induction

Alternating-Current Circuits

Maxwells Equations and Electromagnetic Waves

Properties of Light

Optical Images

Interference and Diffraction

Wave Particle Duality and Quantum Physics

Applications of the Schrodinger Equation

Atoms

Molecules

Relativity

Nuclear Physics

Elementary Particles and the Beginning of the Universe

Filters

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

The resistivity of nichrome at 20ºC is 100 $\times$ 10^-8 $\Omega$ · m.You have nichrome wire whose diameter is 2.50 mm and need a resistance of 100 $\Omega$ .How long would a piece of this wire need to be to provide this resistance?

When a pnp junction transistor is used as an amplifier,a small signal in the _ current results in a large signal in the _ current.

Copper has a mass density of 8.93 g/cm³ and its molar mass is 63.55 g.If each copper atom contributes one free electron,the carrier density is