Question 1

A beam of light falling on a metal surface is causing electrons to be ejected from the surface. If we now double the frequency of the light, which of the following statements are correct? (There could be more than one correct choice.)

Accepted Answer

A)  The kinetic energy of the ejected electrons doubles. 
B)  The speed of the ejected electrons doubles. 
C)  The number of electrons ejected per second doubles. 
D)  Twice as many photons hit the metal surface as before. 
E)  None of the above things occur.

Question 2

What would be the de Broglie wavelength for 1-g object moving at the earth's escape speed 25,000 mph (about 11 km/s)? (h = 6.626 × 10^-34 J ∙ s)

Accepted Answer

The answer of What would be the de Broglie wavelength...

Question 3

When light of wavelength 350 nm is incident on a metal surface, the stopping potential of the photoelectrons is 0.500 V. What is the maximum kinetic energy of these electrons? (c = 3.00 × 108 m/s, h = 6.626 × 10-34 J ∙ s, 1 eV = 1.60 × 10-19 J)

Accepted Answer

A)  0.500 eV 
B)  3.04 eV 
C)  3.54 eV 
D)  4.12 eV

Question 4

If the momentum of an electron is 1.95 × 10-27 kg ∙ m/s, what is its de Broglie wavelength? (h = 6.626 × 10-34 J ∙ s)

Accepted Answer

A)  340 nm 
B)  210 nm 
C)  170 nm 
D)  420 nm 
E)  520 nm

Question 5

Gamma rays are photons with very high energy. What is the wavelength of a gamma-ray photon with energy 7.7 × 10-13 J? (c = 3.0 × 108 m/s, h = 6.626 × 10-34 J ∙ s)

Accepted Answer

A)  2.6 × 10-13 m 
B)  3.9 × 10-13 m 
C)  3.1 × 10-13 m 
D)  3.5 × 10-13 m

Question 6

When it is struck by 240-nm photons, a metal ejects electrons with a maximum kinetic energy of $2.58 \mathrm { eV }$ What is the work function of this material? (c = 3.00 × 108 m/s, h = 6.626 × 10-34 J ∙ s, 1 eV = 16.0 × 10-19 J)

Accepted Answer

A)  2.60 eV 
B)  2.18 eV 
C)  3.02 eV 
D)  3.43 eV

Exam 28: Quantum Physics

A beam of light falling on a metal surface is causing electrons to be ejected from the surface. If we now double the frequency of the light, which of the following statements are correct? (There could be more than one correct choice.)

What would be the de Broglie wavelength for 1-g object moving at the earth's escape speed 25,000 mph (about 11 km/s)? (h = 6.626 × 10^-34 J ∙ s)

When light of wavelength 350 nm is incident on a metal surface, the stopping potential of the photoelectrons is 0.500 V. What is the maximum kinetic energy of these electrons? (c = 3.00 × 10⁸ m/s, h = 6.626 × 10^-34 J ∙ s, 1 eV = 1.60 × 10^-19 J)

If the momentum of an electron is 1.95 × 10^-27 kg ∙ m/s, what is its de Broglie wavelength? (h = 6.626 × 10^-34 J ∙ s)

Gamma rays are photons with very high energy. What is the wavelength of a gamma-ray photon with energy 7.7 × 10^-13 J? (c = 3.0 × 10⁸ m/s, h = 6.626 × 10^-34 J ∙ s)

When it is struck by 240-nm photons, a metal ejects electrons with a maximum kinetic energy of $2.58 \mathrm { eV }$ What is the work function of this material? (c = 3.00 × 10⁸ m/s, h = 6.626 × 10^-34 J ∙ s, 1 eV = 16.0 × 10^-19 J)

Exam 28: Quantum Physics

A beam of light falling on a metal surface is causing electrons to be ejected from the surface. If we now double the frequency of the light, which of the following statements are correct? (There could be more than one correct choice.)

What would be the de Broglie wavelength for 1-g object moving at the earth's escape speed 25,000 mph (about 11 km/s)? (h = 6.626 × 10-34 J ∙ s)

When light of wavelength 350 nm is incident on a metal surface, the stopping potential of the photoelectrons is 0.500 V. What is the maximum kinetic energy of these electrons? (c = 3.00 × 108 m/s, h = 6.626 × 10-34 J ∙ s, 1 eV = 1.60 × 10-19 J)

If the momentum of an electron is 1.95 × 10-27 kg ∙ m/s, what is its de Broglie wavelength? (h = 6.626 × 10-34 J ∙ s)

Gamma rays are photons with very high energy. What is the wavelength of a gamma-ray photon with energy 7.7 × 10-13 J? (c = 3.0 × 108 m/s, h = 6.626 × 10-34 J ∙ s)

When it is struck by 240-nm photons, a metal ejects electrons with a maximum kinetic energy of 2.58eV2.58 \mathrm { eV }2.58eV What is the work function of this material? (c = 3.00 × 108 m/s, h = 6.626 × 10-34 J ∙ s, 1 eV = 16.0 × 10-19 J)

What would be the de Broglie wavelength for 1-g object moving at the earth's escape speed 25,000 mph (about 11 km/s)? (h = 6.626 × 10^-34 J ∙ s)

When light of wavelength 350 nm is incident on a metal surface, the stopping potential of the photoelectrons is 0.500 V. What is the maximum kinetic energy of these electrons? (c = 3.00 × 10⁸ m/s, h = 6.626 × 10^-34 J ∙ s, 1 eV = 1.60 × 10^-19 J)

If the momentum of an electron is 1.95 × 10^-27 kg ∙ m/s, what is its de Broglie wavelength? (h = 6.626 × 10^-34 J ∙ s)

Gamma rays are photons with very high energy. What is the wavelength of a gamma-ray photon with energy 7.7 × 10^-13 J? (c = 3.0 × 10⁸ m/s, h = 6.626 × 10^-34 J ∙ s)

When it is struck by 240-nm photons, a metal ejects electrons with a maximum kinetic energy of $2.58 \mathrm { eV }$ What is the work function of this material? (c = 3.00 × 10⁸ m/s, h = 6.626 × 10^-34 J ∙ s, 1 eV = 16.0 × 10^-19 J)