Question 1

The units of the Planck constant h are those of:

Accepted Answer

A) energy 
B) power 
C) momentum 
D) angular momentum 
E) frequency 
A) energy 
B) power 
C) momentum 
D) angular momentum 
E) frequency

Question 2

The intensity of a light beam with a wavelength of 500 nm is 2000 W/m2.The photon flux is about:

Accepted Answer

A) 5 * 1017 /m2.s 
B) 5 * 1019 /m2.s 
C) 5 *1021 /m2.s 
D) 5 *1023 /m2.s 
E) 5 * 1025 /m2.s 
A) 5 * 1017 /m2.s 
B) 5 * 1019 /m2.s 
C) 5 *1021 /m2.s 
D) 5 *1023 /m2.s 
E) 5 * 1025 /m2.s

Question 3

The diagram shows the graphs of the stopping potential as a function of the frequency of the incident light for photoelectric experiments performed on three different materials.Rank the materials according to the values of their work functions, from least to greatest.

Accepted Answer

A) 1, 2, 3 
B) 3, 2, 1 
C) 2, 3, 1 
D) 2, 1, 3 
E) 1, 3, 2 
A) 1, 2, 3 
B) 3, 2, 1 
C) 2, 3, 1 
D) 2, 1, 3 
E) 1, 3, 2

Question 4

Separate Compton effect experiments are carried out using visible light and x rays.The scattered radiation is observed at the same scattering angle.For these experiments:

Accepted Answer

A) the x rays have the greater shift in wavelength and the greater change in photon energy 
B) the two radiations have the same shift in wavelength and the x rays have the greater change in photon energy 
C) the two radiations have the same shift in wavelength and the visible light has the greater change in photon energy 
D) the two radiations have the same shift in wavelength and the same change in photon energy 
E) the visible light has the greater shift in wavelength and the greater shift in photon energy 
A) the x rays have the greater shift in wavelength and the greater change in photon energy 
B) the two radiations have the same shift in wavelength and the x rays have the greater change in photon energy 
C) the two radiations have the same shift in wavelength and the visible light has the greater change in photon energy 
D) the two radiations have the same shift in wavelength and the same change in photon energy 
E) the visible light has the greater shift in wavelength and the greater shift in photon energy

Question 5

A free electron and a free proton have the same momentum.This means that, compared to the matter wave associated with the proton, the matter wave associated with the electron has:

Accepted Answer

A) a shorter wavelength and a greater frequency 
B) a longer wavelength and a greater frequency 
C) the same wavelength and the same frequency 
D) the same wavelength and a greater frequency 
E) the same wavelength and a smaller frequency 
A) a shorter wavelength and a greater frequency 
B) a longer wavelength and a greater frequency 
C) the same wavelength and the same frequency 
D) the same wavelength and a greater frequency 
E) the same wavelength and a smaller frequency

Question 6

A photon in light beam A has twice the energy of a photon in light beam B.The ratio pA/pB of their momenta is:

Accepted Answer

A) 1/2 
B) 1/4 
C) 1 
D) 2 
E) 4 
A) 1/2 
B) 1/4 
C) 1 
D) 2 
E) 4

Question 7

The reflection coefficient R for a certain barrier tunneling problem is 0.80.The corresponding transmission coefficient T is:

Accepted Answer

A) 0.80 
B) 0.60 
C) 0.50 
D) 0.20 
E) 0 
A) 0.80 
B) 0.60 
C) 0.50 
D) 0.20 
E) 0

Question 8

Which of the following is NOT evidence for the wave nature of matter?

Accepted Answer

A) The photoelectric effect 
B) The diffraction pattern obtained when electrons pass through a slit 
C) Electron tunneling 
D) The validity of the Heisenberg uncertainty principle 
E) The interference pattern obtained when electrons pass through a two-slit system 
A) The photoelectric effect 
B) The diffraction pattern obtained when electrons pass through a slit 
C) Electron tunneling 
D) The validity of the Heisenberg uncertainty principle 
E) The interference pattern obtained when electrons pass through a two-slit system

Question 9

Consider the following three particles:   Rank them according to the wavelengths of their matter waves, least to greatest.

Accepted Answer

A) 1, 2, 3 
B) 3, 2, 1 
C) 2, 3, 1 
D) 1, 3, 2 
E) 1, then 2 and 3 tied 
A) 1, 2, 3 
B) 3, 2, 1 
C) 2, 3, 1 
D) 1, 3, 2 
E) 1, then 2 and 3 tied

Question 10

Which of the following electromagnetic radiations has photons with the greatest energy?

Accepted Answer

A) blue light 
B) yellow light 
C) x rays 
D) radio waves 
E) microwaves 
A) blue light 
B) yellow light 
C) x rays 
D) radio waves 
E) microwaves

Question 11

The wavelength of light beam B is twice the wavelength of light beam B.The energy of a photon in beam A is:

Accepted Answer

A) one-fourth the energy of a photon in beam B 
B) half the energy of photon in beam B 
C) equal to the energy of a photon in beam B 
D) twice energy of a photon in beam B 
E) four times the energy of a photon in beam B 
A) one-fourth the energy of a photon in beam B 
B) half the energy of photon in beam B 
C) equal to the energy of a photon in beam B 
D) twice energy of a photon in beam B 
E) four times the energy of a photon in beam B

Question 12

In a photoelectric effect experiment no electrons are ejected if the frequency of the incident light is less than A/h, where h is the Planck constant and A is:

Accepted Answer

A) the maximum energy needed to eject the least energetic electron 
B) the minimum energy needed to eject the least energetic electron 
C) the maximum energy needed to eject the most energetic electron 
D) the minimum energy needed to eject the most energetic electron 
E) the intensity of the incident light 
A) the maximum energy needed to eject the least energetic electron 
B) the minimum energy needed to eject the least energetic electron 
C) the maximum energy needed to eject the most energetic electron 
D) the minimum energy needed to eject the most energetic electron 
E) the intensity of the incident light

Question 13

Evidence for the wave nature of matter is:

Accepted Answer

A) electron diffraction experiments of Davisson and Germer 
B) Thompson's measurement of e/m 
C) Young's double slit experiment 
D) the Compton effect 
E) Lenz's law 
A) electron diffraction experiments of Davisson and Germer 
B) Thompson's measurement of e/m 
C) Young's double slit experiment 
D) the Compton effect 
E) Lenz's law

Question 14

In Compton scattering from stationary electrons the frequency of the emitted light is independent of:

Accepted Answer

A) the frequency of the incident light 
B) the recoil speed of the electron 
C) the scattering angle 
D) the electron recoil energy 
E) none of the above 
A) the frequency of the incident light 
B) the recoil speed of the electron 
C) the scattering angle 
D) the electron recoil energy 
E) none of the above

Question 15

Of the following which is the best evidence for the wave nature of matter?

Accepted Answer

A) The photoelectric effect 
B) The Compton effect 
C) The spectral radiancy of cavity radiation 
D) The relationship between momentum and energy for an electron 
E) The reflection of electrons by crystals 
A) The photoelectric effect 
B) The Compton effect 
C) The spectral radiancy of cavity radiation 
D) The relationship between momentum and energy for an electron 
E) The reflection of electrons by crystals

Question 16

An electron with energy E is incident on a potential energy barrier of height Epot and thickness L.The probability of tunneling increases if:

Accepted Answer

A) E decreases without any other changes 
B) Epot increases without any other changes 
C) L decreases without any other changes 
D) E and Epot increase by the same amount 
E) E and Epot decrease by the same amount 
A) E decreases without any other changes 
B) Epot increases without any other changes 
C) L decreases without any other changes 
D) E and Epot increase by the same amount 
E) E and Epot decrease by the same amount

Question 17

Electromagnetic radiation with a wavelength of 3.5 * 10-12 m is scattered from stationary electrons, and photons that have been scattered through 50 $\degree$are detected.After a scattering event the magnitude of the photon's momentum is:

Accepted Answer

A) 0 kg.m/s 
B) 8.7 * 10-23 kg.m/s 
C) 1.5* 10-22 kg.m/s 
D) 2.0*10-22 kg.m/s 
E) 2.2 * 10-22 kg.m/s 
A) 0 kg.m/s 
B) 8.7 * 10-23 kg.m/s 
C) 1.5* 10-22 kg.m/s 
D) 2.0*10-22 kg.m/s 
E) 2.2 * 10-22 kg.m/s

Question 18

Of the following, Compton scattering from electrons is most easily observed for:

Accepted Answer

A) microwaves 
B) infrared light 
C) visible light 
D) ultraviolet light 
E) x rays 
A) microwaves 
B) infrared light 
C) visible light 
D) ultraviolet light 
E) x rays

Question 19

In a photoelectric effect experiment at a frequency above cut off, the stopping potential is proportional to:

Accepted Answer

A) the energy of the least energetic electron before it is ejected 
B) the energy of the least energetic electron after it is ejected 
C) the energy of the most energetic electron before it is ejected 
D) the energy of the most energetic electron after it is ejected 
E) the electron potential energy at the surface of the sample 
A) the energy of the least energetic electron before it is ejected 
B) the energy of the least energetic electron after it is ejected 
C) the energy of the most energetic electron before it is ejected 
D) the energy of the most energetic electron after it is ejected 
E) the electron potential energy at the surface of the sample

Question 20

The frequency and wavelength of the matter wave associated with a 10-eV free electron are:

Accepted Answer

A) 1.5 * 1034 Hz, 3.9 *10-10 m 
B) 1.5 *1034 Hz, 1.3 *10-34 m 
C) 2.4 * 1015 Hz, 1.2 *10-9 m 
D) 2.4 *1015 Hz, 3.9 *10-10 m 
E) 4.8 * 1015 Hz, 1.9*10-10 m 
A) 1.5 * 1034 Hz, 3.9 *10-10 m 
B) 1.5 *1034 Hz, 1.3 *10-34 m 
C) 2.4 * 1015 Hz, 1.2 *10-9 m 
D) 2.4 *1015 Hz, 3.9 *10-10 m 
E) 4.8 * 1015 Hz, 1.9*10-10 m

Exam 38: Photons and Matter Waves

The units of the Planck constant h are those of:

The intensity of a light beam with a wavelength of 500 nm is 2000 W/m2.The photon flux is about:

The diagram shows the graphs of the stopping potential as a function of the frequency of the incident light for photoelectric experiments performed on three different materials.Rank the materials according to the values of their work functions, from least to greatest.

Separate Compton effect experiments are carried out using visible light and x rays.The scattered radiation is observed at the same scattering angle.For these experiments:

A free electron and a free proton have the same momentum.This means that, compared to the matter wave associated with the proton, the matter wave associated with the electron has:

A photon in light beam A has twice the energy of a photon in light beam B.The ratio pA/pB of their momenta is:

The reflection coefficient R for a certain barrier tunneling problem is 0.80.The corresponding transmission coefficient T is:

Which of the following is NOT evidence for the wave nature of matter?

Consider the following three particles: Rank them according to the wavelengths of their matter waves, least to greatest.

Which of the following electromagnetic radiations has photons with the greatest energy?

The wavelength of light beam B is twice the wavelength of light beam B.The energy of a photon in beam A is:

In a photoelectric effect experiment no electrons are ejected if the frequency of the incident light is less than A/h, where h is the Planck constant and A is:

Evidence for the wave nature of matter is:

In Compton scattering from stationary electrons the frequency of the emitted light is independent of:

Of the following which is the best evidence for the wave nature of matter?

An electron with energy E is incident on a potential energy barrier of height Epot and thickness L.The probability of tunneling increases if:

Electromagnetic radiation with a wavelength of 3.5 * 10-12 m is scattered from stationary electrons, and photons that have been scattered through 50 °\degree° are detected.After a scattering event the magnitude of the photon's momentum is:

Of the following, Compton scattering from electrons is most easily observed for:

In a photoelectric effect experiment at a frequency above cut off, the stopping potential is proportional to:

The frequency and wavelength of the matter wave associated with a 10-eV free electron are:

Measurement

Motion Along a Straight Line

Vector

Motion in Two and Three Dimensions

Force and Motion I

Force and Motion II

Kinetic Energy and Work

Potential Energy and Conservation of Energy

Center of Mass and Linear Momentum

Rotation

Rolling, Torque, and Angular Momentum

Equilibrium and Elasticity

Gravitation

Fluids

Oscillations

Waves I

Waves II

Temperature, Heat, and the First Law of Thermodynamics

The Kinetic Theory of Gases

Entropy and the Second Law of Thermodynamics

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Electric Fields

Gauss Law

Electric Potential

Capacitance

Current and Resistance

Circuits

Magnetic Fields

Magnetic Fields Due to Currents

Induction and Inductance

Electromagnetic Oscillations and Alternating Current

Maxwells Equations; Magnetism of Matter

Electromagnetic Waves

Images

Interference

Diffraction

Relativity

More About Matter Waves

All About Atoms

Conduction of Electricity in Solids

Nuclear Physics

Energy From the Nucleus

Quarks, Leptons, and the Big Bang

Filters

The intensity of a light beam with a wavelength of 500 nm is 2000 W/m².The photon flux is about:

A photon in light beam A has twice the energy of a photon in light beam B.The ratio p_A/p_B of their momenta is:

An electron with energy E is incident on a potential energy barrier of height E_pot and thickness L.The probability of tunneling increases if:

Electromagnetic radiation with a wavelength of 3.5 * 10^-12 m is scattered from stationary electrons, and photons that have been scattered through 50 $\degree$ are detected.After a scattering event the magnitude of the photon's momentum is: