Question 1

The momentum of a 20-MeV electron is approximately

Accepted Answer

A)  1.6 * 10-21 kg · m/s 
B)  2.4 *10-42 kg · m/s 
C)  5.8 * 10-42 kg · m/s 
D)  2.4 * 10-21 kg · m/s 
E)  5.8*10-21 kg · m/s 
A)  1.6 * 10-21 kg · m/s 
B)  2.4 *10-42 kg · m/s 
C)  5.8 * 10-42 kg · m/s 
D)  2.4 * 10-21 kg · m/s 
E)  5.8*10-21 kg · m/s

Question 2

Suppose that a 40-kg runner in an imaginary world in which Planck's constant has the value 100 J · s must be located at the finish line to an accuracy of ± 0.33 m to be sure that it won the race. What would be the minimal uncertainty in its speed in that world?

Accepted Answer

A)  0.12 m/s 
B)  0.13 m/s 
C)  0.60 m/s 
D)  1.2 m/s 
E)  15 m/s 
A)  0.12 m/s 
B)  0.13 m/s 
C)  0.60 m/s 
D)  1.2 m/s 
E)  15 m/s

Question 3

With a microscope using photons you locate an electron in an atom to within a distance of 0.010 nm. The uncertainty in the momentum of the electron is approximately

Accepted Answer

A)  1.1 *10-24 N · s 
B)  5.3 * 10-27 N · s 
C)  5.3 * 10-24 N · s 
D)  4.2 * 10-24 N · s 
E)  1.1 *10-23 N · s 
A)  1.1 *10-24 N · s 
B)  5.3 * 10-27 N · s 
C)  5.3 * 10-24 N · s 
D)  4.2 * 10-24 N · s 
E)  1.1 *10-23 N · s

Question 4

An electron is in a one-dimensional box of length 0.5 nm. The wavelength of the photon emitted as the electron transitions from its second excited state to its ground state is

Accepted Answer

A)  103 nm 
B)  274 nm 
C)  365 nm 
D)  402 nm 
E)  521 nm 
A)  103 nm 
B)  274 nm 
C)  365 nm 
D)  402 nm 
E)  521 nm

Question 5

In a Compton scattering experiment, an 8.00-MeV incident photon is scattered at an angle of 15º with energy of 5.20 MeV. The kinetic energy of the recoil electron is

Accepted Answer

A)  2.80 MeV 
B)  2.08 MeV 
C)  5.20 MeV 
D)  7.28 MeV 
E)  800 MeV 
A)  2.80 MeV 
B)  2.08 MeV 
C)  5.20 MeV 
D)  7.28 MeV 
E)  800 MeV

Question 6

The fact that particles have a wave nature was first verified by

Accepted Answer

A)  the Heisenberg uncertainty principle. 
B)  Davisson and Germer's diffraction of electrons experiment. 
C)  blackbody radiation studies. 
D)  the Bohr theory of the atom. 
E)  the photoelectric effect. 
A)  the Heisenberg uncertainty principle. 
B)  Davisson and Germer's diffraction of electrons experiment. 
C)  blackbody radiation studies. 
D)  the Bohr theory of the atom. 
E)  the photoelectric effect.

Question 7

The man whose name is most closely associated with the explanation of the photoelectric effect is

Accepted Answer

A)  M. Planck. 
B)  E. Fermi. 
C)  N. Bohr. 
D)  E. Rutherford. 
E)  A. Einstein. 
A)  M. Planck. 
B)  E. Fermi. 
C)  N. Bohr. 
D)  E. Rutherford. 
E)  A. Einstein.

Question 8

An X-ray photon scattering off an electron imparts some of its energy to the electron (the Compton effect). Which of the following statements is true?

Accepted Answer

A)  The wavelength of the scattered photon is unchanged. 
B)  The wavelength of the scattered photon is decreased. 
C)  The wavelength of the scattered photon is increased. 
D)  The scattered photon gains speed. 
E)  The scattered photon is slowed. 
A)  The wavelength of the scattered photon is unchanged. 
B)  The wavelength of the scattered photon is decreased. 
C)  The wavelength of the scattered photon is increased. 
D)  The scattered photon gains speed. 
E)  The scattered photon is slowed.

Question 9

An electron in the hydrogen atom makes a transition from an energy level of -1.51 eV to one of energy -3.40 eV. In this process a photon is emitted with what wavelength?

Accepted Answer

A)  1.89 nm 
B)  656 nm 
C)  456 nm 
D)  821 nm 
E)  365 nm 
A)  1.89 nm 
B)  656 nm 
C)  456 nm 
D)  821 nm 
E)  365 nm

Question 10

The wavelength of red light is closest to

Accepted Answer

A)  100 nm 
B)  300 nm 
C)  500 nm 
D)  700 nm 
E)  900 nm 
A)  100 nm 
B)  300 nm 
C)  500 nm 
D)  700 nm 
E)  900 nm

Question 11

An alpha particle (mass = 4 amu) is moving twice as fast as a proton (mass = 1 amu). Calculate the de Broglie wavelength of the proton divided by the de Broglie wavelength of the alpha particle.

Accepted Answer

A)  1/4 
B)  8 
C)  1/8 
D)  2 
E)  1/2 
A)  1/4 
B)  8 
C)  1/8 
D)  2 
E)  1/2

Question 12

The energy of the electron in a hydrogen atom in the ground state is -13.6 eV. If the potential is modeled like a one-dimensional box, the width of the box is

Accepted Answer

A)  0.0529 nm 
B)  0.523 nm 
C)  0.324 nm 
D)  0.166 nm 
E)  None of these is correct. 
A)  0.0529 nm 
B)  0.523 nm 
C)  0.324 nm 
D)  0.166 nm 
E)  None of these is correct.

Question 13

Which of the following formulas has the correct units for the linear momentum of a photon?

Accepted Answer

A)  hc/$\lambda$ 
B)  c/n 
C)  l/$\lambda$ 
D) $\lambda$/h 
E)  None of these is correct. 
A)  hc/$\lambda$ 
B)  c/n 
C)  l/$\lambda$ 
D) $\lambda$/h 
E)  None of these is correct.

Question 14

The normalized wave function corresponding to n = 3 for a particle in a box is shown in

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
E)  5 
A)  1 
B)  2 
C)  3 
D)  4 
E)  5

Question 15

A proton is in a one-dimensional box of length 2 * 10-15 m. What is the value of the energy of the n = 5 state divided by the energy of the n = 3 state?

Accepted Answer

A)  1.7 
B)  16 
C)  2.8 
D)  2.0 
E)  0.4 
A)  1.7 
B)  16 
C)  2.8 
D)  2.0 
E)  0.4

Question 16

An electron is sent through a slit whose width is $\Delta$x = 0.040 cm. The uncertainty in the x component of the momentum of this electron is approximately

Accepted Answer

A)  1.3 * 10-24 N · s 
B)  2.6 * 10-24 N · s 
C)  1.3 *10-23 N · s 
D)  2.6 * 10-23 N · s 
E)  3.9 *10-25 N · s 
A)  1.3 * 10-24 N · s 
B)  2.6 * 10-24 N · s 
C)  1.3 *10-23 N · s 
D)  2.6 * 10-23 N · s 
E)  3.9 *10-25 N · s

Question 17

Photons of wavelength 0.00150 nm undergo Compton collisions with free electrons. What is the energy of the scattered photons whose angle of scattering is 60º?

Accepted Answer

A)  13.3 * 10-14 J 
B)  3.27 *10-14 J 
C)  28.0 * 10-14 J 
D)  7.36 * 10-14 J 
E)  2.14 *10-14 J 
A)  13.3 * 10-14 J 
B)  3.27 *10-14 J 
C)  28.0 * 10-14 J 
D)  7.36 * 10-14 J 
E)  2.14 *10-14 J

Question 18

An electron is in a one-dimensional box of length 0.5 nm. The wavelength of the photon emitted as the electron transitions from its first excited state to its ground state is

Accepted Answer

A)  103 nm 
B)  274 nm 
C)  365 nm 
D)  402 nm 
E)  521 nm 
A)  103 nm 
B)  274 nm 
C)  365 nm 
D)  402 nm 
E)  521 nm

Question 19

Classical electromagnetic theory was successful in explaining or predicting only one of the characteristics or experimental results of photoelectric emission. These graphs illustrate these main experimental results. Which one is in agreement with predictions of classical electromagnetic theory?

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
E)  None of these is correct. 
A)  1 
B)  2 
C)  3 
D)  4 
E)  None of these is correct.

Question 20

Light of wavelength 400 nm is incident on a certain metal. The stopping potential for the emitted electrons is measured to be 1.2 V. What is the work function of this metal? (Planck's constant h = 6.626 * 10-34 J · s = 4.136 * 10-15 eV s.)

Accepted Answer

A)  4.3 eV 
B)  3.1 eV 
C)  1.9 eV 
D)  1.2 eV 
E)  0.95 eV 
A)  4.3 eV 
B)  3.1 eV 
C)  1.9 eV 
D)  1.2 eV 
E)  0.95 eV

Exam 14: Wave Particle Duality and Quantum Physics

The momentum of a 20-MeV electron is approximately

Suppose that a 40-kg runner in an imaginary world in which Planck's constant has the value 100 J · s must be located at the finish line to an accuracy of ± 0.33 m to be sure that it won the race. What would be the minimal uncertainty in its speed in that world?

With a microscope using photons you locate an electron in an atom to within a distance of 0.010 nm. The uncertainty in the momentum of the electron is approximately

An electron is in a one-dimensional box of length 0.5 nm. The wavelength of the photon emitted as the electron transitions from its second excited state to its ground state is

In a Compton scattering experiment, an 8.00-MeV incident photon is scattered at an angle of 15º with energy of 5.20 MeV. The kinetic energy of the recoil electron is

The fact that particles have a wave nature was first verified by

The man whose name is most closely associated with the explanation of the photoelectric effect is

An X-ray photon scattering off an electron imparts some of its energy to the electron (the Compton effect). Which of the following statements is true?

An electron in the hydrogen atom makes a transition from an energy level of -1.51 eV to one of energy -3.40 eV. In this process a photon is emitted with what wavelength?

The wavelength of red light is closest to

An alpha particle (mass = 4 amu) is moving twice as fast as a proton (mass = 1 amu). Calculate the de Broglie wavelength of the proton divided by the de Broglie wavelength of the alpha particle.

The energy of the electron in a hydrogen atom in the ground state is -13.6 eV. If the potential is modeled like a one-dimensional box, the width of the box is

Which of the following formulas has the correct units for the linear momentum of a photon?

The normalized wave function corresponding to n = 3 for a particle in a box is shown in

A proton is in a one-dimensional box of length 2 * 10-15 m. What is the value of the energy of the n = 5 state divided by the energy of the n = 3 state?

An electron is sent through a slit whose width is Δ\DeltaΔ x = 0.040 cm. The uncertainty in the x component of the momentum of this electron is approximately

Photons of wavelength 0.00150 nm undergo Compton collisions with free electrons. What is the energy of the scattered photons whose angle of scattering is 60º?

An electron is in a one-dimensional box of length 0.5 nm. The wavelength of the photon emitted as the electron transitions from its first excited state to its ground state is

Classical electromagnetic theory was successful in explaining or predicting only one of the characteristics or experimental results of photoelectric emission. These graphs illustrate these main experimental results. Which one is in agreement with predictions of classical electromagnetic theory?

Light of wavelength 400 nm is incident on a certain metal. The stopping potential for the emitted electrons is measured to be 1.2 V. What is the work function of this metal? (Planck's constant h = 6.626 * 10-34 J · s = 4.136 * 10-15 eV s.)

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

Applications of the Schrodinger Equation

Atoms

Molecules

Solids and the Theory of Conduction

Relativity

Nuclear Physics

Elementary Particles and the Beginning of the Universe

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A proton is in a one-dimensional box of length 2 * 10^-15 m. What is the value of the energy of the n = 5 state divided by the energy of the n = 3 state?

An electron is sent through a slit whose width is $\Delta$ x = 0.040 cm. The uncertainty in the x component of the momentum of this electron is approximately

Light of wavelength 400 nm is incident on a certain metal. The stopping potential for the emitted electrons is measured to be 1.2 V. What is the work function of this metal? (Planck's constant h = 6.626 * 10^-34 J · s = 4.136 * 10^-15 eV s.)