Question 1

What is the shortest x-ray wavelength that can be produced in a 12-keV x-ray machine?

Accepted Answer

The answer of What is the shortest x-ray wavelength that...

Question 2

Assume we can determine the position of a particle within an uncertainty of 0.5 nm. What will be the resulting uncertainty in the particle's momentum (in kg ⋅ m/s)?

Accepted Answer

A)  1.9 × 10−25 
B)  4.2 × 10−25 
C)  1.1 × 10−25 
D)  1.3 × 10−24 
E)  6.6 × 10−25 
A)  1.9 × 10−25 
B)  4.2 × 10−25 
C)  1.1 × 10−25 
D)  1.3 × 10−24 
E)  6.6 × 10−25 C

Question 3

What is the maximum kinetic energy (in eV) of a photoelectron when a surface, whose work function is 5.0 eV, is illuminated by photons whose wavelength is 400 nm?

Accepted Answer

A)  3.1 
B)  −1.9 
C)  1.9 
D)  0 
E)  1.2 
A)  3.1 
B)  −1.9 
C)  1.9 
D)  0 
E)  1.2 D

Question 4

In electron diffraction, an electron moving at speed v << c acts like

Accepted Answer

A)  a particle with momentum mv. 
B)  a particle with position coordinate v/t. 
C)  a wave with wavelength v/t. 
D)  a wave with wavelength h/mv. 
E)  both a particle with position coordinate v/t and a wave with wavelength v/t. 
A)  a particle with momentum mv. 
B)  a particle with position coordinate v/t. 
C)  a wave with wavelength v/t. 
D)  a wave with wavelength h/mv. 
E)  both a particle with position coordinate v/t and a wave with wavelength v/t.

Question 5

If the position of an electron (m = 9.11 × 10−31 kg) could be measured to within 10−30 m, the uncertainty in the magnitude of its speed could be as much as

Accepted Answer

A)  6 × 10−34 m/s. 
B)  6 × 1025 m/s. 
C)  6 × 1030 m/s. 
D)  1031 m/s. 
E)  1061 m/s. 
A)  6 × 10−34 m/s. 
B)  6 × 1025 m/s. 
C)  6 × 1030 m/s. 
D)  1031 m/s. 
E)  1061 m/s.

Question 6

How much energy is in a 63 kHz photon of AM-radiation?

Accepted Answer

A)  1.0 × 10−38 J 
B)  6.6 × 10−30 J 
C)  4.2 × 10−29 J 
D)  3.1 × 10−30 J 
E)  13 × 10−29 J 
A)  1.0 × 10−38 J 
B)  6.6 × 10−30 J 
C)  4.2 × 10−29 J 
D)  3.1 × 10−30 J 
E)  13 × 10−29 J

Question 7

The light intensity incident on a metallic surface with a work function of 3 eV produces photoelectrons with a maximum kinetic energy of 2 eV. The frequency of the light is doubled. Determine the maximum kinetic energy (in eV).

Accepted Answer

A)  3 
B)  2 
C) 
  
D)  4 
E)  7 
A)  3 
B)  2 
C) 
  
D)  4 
E)  7

Question 8

Find the uncertainty in the momentum (in kg ⋅ m/s) of an electron if the uncertainty in its position is equal to 3.4 × 10−10 m, the circumference of the first Bohr orbit.

Accepted Answer

A)  6.2 × 10−25 
B)  1.6 × 10−25 
C)  15.5 × 10−25 
D)  19.4 × 10−25 
E)  2.0 × 10−24 
A)  6.2 × 10−25 
B)  1.6 × 10−25 
C)  15.5 × 10−25 
D)  19.4 × 10−25 
E)  2.0 × 10−24

Question 9

An electron is sitting on a pinpoint having a diameter of 2.5 μm. What is the minimum uncertainty in the speed of the electron?

Accepted Answer

The answer of An electron is sitting on a pinpoint...

Question 10

When a photon collides with a free electron at rest and the direction of motion of the photon changes,

Accepted Answer

A)  the magnitude of the momentum of the photon does not change. 
B)  the momentum of the electron does not change. 
C)  the kinetic energy of the electron does not change. 
D)  the total energy of the photon does not change. 
E)  both the magnitude of the momentum and the total energy of the photon decrease. 
A)  the magnitude of the momentum of the photon does not change. 
B)  the momentum of the electron does not change. 
C)  the kinetic energy of the electron does not change. 
D)  the total energy of the photon does not change. 
E)  both the magnitude of the momentum and the total energy of the photon decrease.

Question 11

A helium-neon laser emits red light having a wavelength of 6.4 × 10−7 m and a power of 0.5 mW. How many photons are emitted each second?

Accepted Answer

A)  6.4 × 1038 
B)  1.6 × 1021 
C)  3.2 × 1025 
D)  2.6 × 1018 
E)  1.6 × 1015 
A)  6.4 × 1038 
B)  1.6 × 1021 
C)  3.2 × 1025 
D)  2.6 × 1018 
E)  1.6 × 1015

Question 12

If a rubidium surface is irradiated with blue light of wavelength 450.0 nm, what is the kinetic energy of the electrons emitted? (The work function for rubidium is φ = 2.09 eV.)

Accepted Answer

The answer of If a rubidium surface is irradiated with...

Question 13

A photon collides with an electron. After the collision the wavelength of the scattered wave at a scattering angle greater than   is

Accepted Answer

A)  greater than or equal to the initial wavelength. 
B)  equal to the initial wavelength. 
C)  less than or equal to the initial wavelength. 
D)  greater than the initial wavelength. 
E)  less or greater depending on the scattering angle. 
A)  greater than or equal to the initial wavelength. 
B)  equal to the initial wavelength. 
C)  less than or equal to the initial wavelength. 
D)  greater than the initial wavelength. 
E)  less or greater depending on the scattering angle.

Question 14

What is the maximum kinetic energy (in eV) of a photoelectron emitted from a surface whose work function is 5.0 eV when illuminated by a light whose wavelength is 200 nm?

Accepted Answer

A)  1.9 
B)  1.2 
C)  3.1 
D)  zero 
E)  6.2 
A)  1.9 
B)  1.2 
C)  3.1 
D)  zero 
E)  6.2

Question 15

A solid state pulsed laser has an energy of 400 mJ per pulse. If its wavelength is 1.06 × 10−6 m, how many photons are in each pulse?

Accepted Answer

A)  2 × 1025 
B)  2 × 1021 
C)  3 × 1018 
D)  6 × 1038 
E)  2 × 1018 
A)  2 × 1025 
B)  2 × 1021 
C)  3 × 1018 
D)  6 × 1038 
E)  2 × 1018

Question 16

A neutron has a mass of 1.67 × 10−27 kg. Its de Broglie wavelength is 1.4 × 10−10 m. What temperature would it correspond to if we had a monatomic gas having the same average kinetic energy (in °C)?

Accepted Answer

A)  273 
B)  25 
C)  36 
D)  309 
E)  51 
A)  273 
B)  25 
C)  36 
D)  309 
E)  51

Question 17

Microscopes are inherently limited by the wavelength of the light used. How much smaller (in order of magnitude) can we "see" using an electron microscope whose electrons have been accelerated through a potential difference of 50000 V than using red light (500 nm)?

Accepted Answer

A)  3 
B)  4 
C)  5 
D)  6 
E)  14 
A)  3 
B)  4 
C)  5 
D)  6 
E)  14

Question 18

The light intensity incident on a metallic surface produces photoelectrons with a maximum kinetic energy of 2 eV. The light intensity is doubled. Determine the maximum kinetic energy of the photoelectrons (in eV).

Accepted Answer

A)  4 
B)  2 
C) 
  
D)  3 
E)  16 
A)  4 
B)  2 
C) 
  
D)  3 
E)  16

Question 19

The "seeing ability" or resolution of radiation is determined by its wavelength. If an atom is approximately 10−10 m in diameter, how fast must an electron travel to have a wavelength smaller than the size of an atom?

Accepted Answer

Question 20

A stopping potential of 3.2 V is needed for radiation whose wavelength is 200 nm. What is the work function (in eV) of the material?

Accepted Answer

A)  4.0 
B)  3.0 
C)  5.0 
D)  6.0 
E)  2.0 
A)  4.0 
B)  3.0 
C)  5.0 
D)  6.0 
E)  2.0

Exam 40: Introduction to Quantum Physics

What is the shortest x-ray wavelength that can be produced in a 12-keV x-ray machine?

Assume we can determine the position of a particle within an uncertainty of 0.5 nm. What will be the resulting uncertainty in the particle's momentum (in kg ⋅ m/s)?

What is the maximum kinetic energy (in eV) of a photoelectron when a surface, whose work function is 5.0 eV, is illuminated by photons whose wavelength is 400 nm?

In electron diffraction, an electron moving at speed v << c acts like

If the position of an electron (m = 9.11 × 10−31 kg) could be measured to within 10−30 m, the uncertainty in the magnitude of its speed could be as much as

How much energy is in a 63 kHz photon of AM-radiation?

The light intensity incident on a metallic surface with a work function of 3 eV produces photoelectrons with a maximum kinetic energy of 2 eV. The frequency of the light is doubled. Determine the maximum kinetic energy (in eV).

Find the uncertainty in the momentum (in kg ⋅ m/s) of an electron if the uncertainty in its position is equal to 3.4 × 10−10 m, the circumference of the first Bohr orbit.

An electron is sitting on a pinpoint having a diameter of 2.5 μm. What is the minimum uncertainty in the speed of the electron?

When a photon collides with a free electron at rest and the direction of motion of the photon changes,

A helium-neon laser emits red light having a wavelength of 6.4 × 10−7 m and a power of 0.5 mW. How many photons are emitted each second?

If a rubidium surface is irradiated with blue light of wavelength 450.0 nm, what is the kinetic energy of the electrons emitted? (The work function for rubidium is φ = 2.09 eV.)

A photon collides with an electron. After the collision the wavelength of the scattered wave at a scattering angle greater than is

What is the maximum kinetic energy (in eV) of a photoelectron emitted from a surface whose work function is 5.0 eV when illuminated by a light whose wavelength is 200 nm?

A solid state pulsed laser has an energy of 400 mJ per pulse. If its wavelength is 1.06 × 10−6 m, how many photons are in each pulse?

A neutron has a mass of 1.67 × 10−27 kg. Its de Broglie wavelength is 1.4 × 10−10 m. What temperature would it correspond to if we had a monatomic gas having the same average kinetic energy (in °C)?

Microscopes are inherently limited by the wavelength of the light used. How much smaller (in order of magnitude) can we "see" using an electron microscope whose electrons have been accelerated through a potential difference of 50000 V than using red light (500 nm)?

The light intensity incident on a metallic surface produces photoelectrons with a maximum kinetic energy of 2 eV. The light intensity is doubled. Determine the maximum kinetic energy of the photoelectrons (in eV).

The "seeing ability" or resolution of radiation is determined by its wavelength. If an atom is approximately 10−10 m in diameter, how fast must an electron travel to have a wavelength smaller than the size of an atom?

A stopping potential of 3.2 V is needed for radiation whose wavelength is 200 nm. What is the work function (in eV) of the material?

Physics and Measurement

Motion in One Dimension

Vectors

Motion in Two Dimensions

The Laws of Motion

Circular Motion and Other Applications of Newtons Laws

Energy of a System

Conservation of Energy

Linear Momentum and Collisions

Rotation of a Rigid Object About a Fixed Axis

Angular Momentum

Static Equilibrium and Elasticity

Universal Gravitation

Fluid Mechanics

Oscillatory Motion

Wave Motion

Superposition and Standing Waves

Temperature

The First Law of Thermodynamics

The Kinetic Theory of Gases

Heat Engines, Entropy, and the Second Law of Thermodynamics

Electric Fields

Gausss Law

Electric Potential

Capacitance and Dielectrics

Current and Resistance

Direct-Current Circuits

Magnetic Fields

Sources of the Magnetic Field

Faradays Law

Inductance

Alternating-Current Circuits

Electromagnetic Waves

The Nature of Light and the Principles of Ray Optics

Image Formation

Wave Optics

Diffraction Patterns and Polarization

Relativity

Quantum Mechanics

Atomic Physics

Molecules and Solids

Nuclear Structure

Particle Physics and Cosmology

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If the position of an electron (m = 9.11 × 10−³¹ kg) could be measured to within 10−³⁰ m, the uncertainty in the magnitude of its speed could be as much as

Find the uncertainty in the momentum (in kg ⋅ m/s) of an electron if the uncertainty in its position is equal to 3.4 × 10−¹⁰ m, the circumference of the first Bohr orbit.

A helium-neon laser emits red light having a wavelength of 6.4 × 10−⁷ m and a power of 0.5 mW. How many photons are emitted each second?

A solid state pulsed laser has an energy of 400 mJ per pulse. If its wavelength is 1.06 × 10−⁶ m, how many photons are in each pulse?

A neutron has a mass of 1.67 × 10−²⁷ kg. Its de Broglie wavelength is 1.4 × 10−¹⁰ m. What temperature would it correspond to if we had a monatomic gas having the same average kinetic energy (in °C)?

The "seeing ability" or resolution of radiation is determined by its wavelength. If an atom is approximately 10−¹⁰ m in diameter, how fast must an electron travel to have a wavelength smaller than the size of an atom?