Exam 28: Quantum Physics

A laser pulse of duration 25 ms has a total energy of 1.4 J. If the wavelength of this radiation is 567 nm, how many photons are emitted in one pulse? (c = 3.00 × 10⁸ m/s, h = 6.626 × 10^-34 J ∙ s)

Free

(Multiple Choice)

4.9/5

(81)

Question 1

Correct Answer:

Verified

A certain crystal has a spacing of 0.442 nm between atoms. A beam of neutrons moving with a speed of 1640 m/s perpendicular to the surface is diffracted as it passes through the crystal. What is the angle from the central maximum to the next interference maximum? (m_neutron = 1.675 × 10^-27 kg, h = 6.626 × 10^-34 J ∙ s)

Free

(Multiple Choice)

4.9/5

(84)

Question 2

Correct Answer:

Verified

The work function of a particular metal is $4.20 \times 10 ^ { - 19 } \mathrm {~J}$ What is the photoelectric cutoff (threshold) wavelength for this metal? (c = 3.00 × 10⁸ m/s, h = 6.626 × 10^-34 J ∙ s)

Free

(Multiple Choice)

4.7/5

(87)

Question 3

Correct Answer:

Verified

Protons are being accelerated in a particle accelerator. When the speed of the protons is doubled, their de Broglie wavelength will

(Multiple Choice)

4.7/5

(76)

Question 4

Light of a given wavelength is used to illuminate the surface of a metal, however, no photoelectrons are emitted. In order to cause electrons to be ejected from the surface of this metal you should

(Multiple Choice)

4.8/5

(83)

Question 5

For a certain metal, light of frequency 7.24 × 10^-14 Hz is just barely able to dislodge photoelectrons from the metal. (h = 6.626 × 10^-34 J ∙ s, 1 eV = 1.60 × 10^-19 J, e = 1.60 × 10^-19C) (a) What will be the stopping potential if light of frequency 8.75 × 10^-14 Hz is shone on the metal? (b) What is the work function (in electron-volts) of this metal?

(Short Answer)

4.9/5

(70)

Question 6

Gamma rays are photons with very high energy. How many visible-light photons with a wavelength of 500 nm would you need to equal the energy of a gamma-ray photon with energy $4.1 \times 10 ^{- 13} \mathrm {~J} ?$

(Multiple Choice)

5.0/5

(74)

Question 7

After an electron has been accelerated through a potential difference of 0.15 kV, what is its de Broglie wavelength? (e = 1.60 × 10^-19 C, m_electron = 9.11 × 10^-31 kg, h = 6.626 × 10^-34 J ∙ s)

(Multiple Choice)

4.8/5

(61)

Question 8

If a proton and an electron have the same de Broglie wavelengths, which one is moving faster?

(Multiple Choice)

4.9/5

(73)

Question 9

The work function of a certain metal is 1.90 eV. What is the longest wavelength of light that can cause photoelectron emission from this metal? (1 eV = 1.60 × 10^-19 J, c = 3.00 × 10⁸ m/s, h = 6.626 × 10^-34 J ∙ s)

(Multiple Choice)

5.0/5

(76)

Question 10

When the surface of a metal is exposed to blue light, electrons are emitted. If the intensity of the blue light is increased, which of the following things will also increase?

(Multiple Choice)

4.8/5

(76)

Question 11

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 threshold (cutoff) frequency of this metal? (c = 3.00 × 10⁸ m/s, h = 6.626 × 10^-34 J ∙ s, 1 eV = 1.60 × 10^-19 J)

(Multiple Choice)

4.8/5

(78)

Question 12

When it is struck by 240-nm photons, a material having a work function of 2.60 eV emits electrons. What is the maximum kinetic energy of the emitted electrons? (c = 3.00 × 10⁸ m/s, h = 6.626 × 10^-34 J ∙ s, 1 eV = 1.60 × 10^-19 J)

(Multiple Choice)

4.9/5

(88)

Question 13

A proton and an electron are both accelerated to the same final speed. If λ_p is the de Broglie wavelength of the proton and λ_e is the de Broglie wavelength of the electron, then

(Multiple Choice)

4.8/5

(86)

Question 14

Calculate the kinetic energy, in electron-volts, of a neutron that has a de Broglie wavelength of $7.2 \times 10 ^{- 12 }\mathrm {~m}$ (m_neutron = 1.675 × 10^-27 kg, 1 eV = 1.6 × 10^-19 J, h = 6.626 × 10^-34J ∙ s)

(Short Answer)

4.9/5

(75)

Question 15

If the longest wavelength of light that is able to dislodge electrons from a metal is 373 nm, what is the work function of that metal, in electron-volts? (1 eV = 1.60 × 10^-19 J, c = 3.00 × 10⁸ m/s, h = 6.626 × 10^-34 J ∙ s)

(Short Answer)

4.9/5

(83)

Question 16

How "slow" must a 200-g ball move to have a de Broglie wavelength of 1.0 mm? (h = 6.626 × 10^-34 J ∙ s)

(Short Answer)

4.8/5

(75)

Question 17

Electrons with a speed of 2.1 × 10⁶ m/s are directed towards a 1.0-μm wide slit. An electron detector is placed 1.0 m behind the slit. How wide is the central maximum of the electron diffraction pattern on the detector? (h = 6.626 × 10^-34 J ∙ s, m_electron = 9.11 × 10^-31 kg)

(Multiple Choice)

4.8/5

(79)

Question 18

What is the wavelength of the matter wave associated with an electron moving with a speed of 2.5 × 10⁷ m/s? (m_electron = 9.11 × 10^-31 kg, h = 6.626 × 10^-34 J ∙ s)

(Multiple Choice)

4.9/5

(70)

Question 19

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

(Multiple Choice)

4.8/5

(65)

Question 20

Showing 1 - 20 of 86

Exam 28: Quantum Physics

A laser pulse of duration 25 ms has a total energy of 1.4 J. If the wavelength of this radiation is 567 nm, how many photons are emitted in one pulse? (c = 3.00 × 108 m/s, h = 6.626 × 10-34 J ∙ s)

The work function of a particular metal is 4.20×10−19 J4.20 \times 10 ^ { - 19 } \mathrm {~J}4.20×10−19 J What is the photoelectric cutoff (threshold) wavelength for this metal? (c = 3.00 × 108 m/s, h = 6.626 × 10-34 J ∙ s)

Protons are being accelerated in a particle accelerator. When the speed of the protons is doubled, their de Broglie wavelength will

Light of a given wavelength is used to illuminate the surface of a metal, however, no photoelectrons are emitted. In order to cause electrons to be ejected from the surface of this metal you should

Gamma rays are photons with very high energy. How many visible-light photons with a wavelength of 500 nm would you need to equal the energy of a gamma-ray photon with energy 4.1×10−13 J?4.1 \times 10 ^{- 13} \mathrm {~J} ?4.1×10−13 J?

After an electron has been accelerated through a potential difference of 0.15 kV, what is its de Broglie wavelength? (e = 1.60 × 10-19 C, melectron = 9.11 × 10-31 kg, h = 6.626 × 10-34 J ∙ s)

If a proton and an electron have the same de Broglie wavelengths, which one is moving faster?

The work function of a certain metal is 1.90 eV. What is the longest wavelength of light that can cause photoelectron emission from this metal? (1 eV = 1.60 × 10-19 J, c = 3.00 × 108 m/s, h = 6.626 × 10-34 J ∙ s)

When the surface of a metal is exposed to blue light, electrons are emitted. If the intensity of the blue light is increased, which of the following things will also increase?

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 threshold (cutoff) frequency of this metal? (c = 3.00 × 108 m/s, h = 6.626 × 10-34 J ∙ s, 1 eV = 1.60 × 10-19 J)

When it is struck by 240-nm photons, a material having a work function of 2.60 eV emits electrons. What is the maximum kinetic energy of the emitted electrons? (c = 3.00 × 108 m/s, h = 6.626 × 10-34 J ∙ s, 1 eV = 1.60 × 10-19 J)

A proton and an electron are both accelerated to the same final speed. If λp is the de Broglie wavelength of the proton and λe is the de Broglie wavelength of the electron, then

Calculate the kinetic energy, in electron-volts, of a neutron that has a de Broglie wavelength of 7.2×10−12 m7.2 \times 10 ^{- 12 }\mathrm {~m}7.2×10−12 m (mneutron = 1.675 × 10-27 kg, 1 eV = 1.6 × 10-19 J, h = 6.626 × 10-34 J ∙ s)

If the longest wavelength of light that is able to dislodge electrons from a metal is 373 nm, what is the work function of that metal, in electron-volts? (1 eV = 1.60 × 10-19 J, c = 3.00 × 108 m/s, h = 6.626 × 10-34 J ∙ s)

How "slow" must a 200-g ball move to have a de Broglie wavelength of 1.0 mm? (h = 6.626 × 10-34 J ∙ s)

Electrons with a speed of 2.1 × 106 m/s are directed towards a 1.0-μm wide slit. An electron detector is placed 1.0 m behind the slit. How wide is the central maximum of the electron diffraction pattern on the detector? (h = 6.626 × 10-34 J ∙ s, melectron = 9.11 × 10-31 kg)

What is the wavelength of the matter wave associated with an electron moving with a speed of 2.5 × 107 m/s? (melectron = 9.11 × 10-31 kg, 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 measured to be 0.500 V. What is the work function of this metal? (c = 3.00 × 108 m/s, h = 6.626 × 10-34 J ∙ s, 1 eV = 1.60 × 10-19 J)

Representing Motion

Motion in One Dimension

Vectors and Motion in Two Dimensions

Forces and Newtons Laws of Motion

Applying Newtons Laws

Gravity

Rotational Motion

Equilibrium Ad Elasticity

Momentum

Energy and Work

Using Energy

Thermal Properties of Matter

Fluids

Oscillations

Traveling Waves and Sound

Superposition and Standing Waves

Wave Optics

Ray Optics

Optical Instruments

Electric Fields and Forces

Electric Potential

Current and Resistance

Circuits

Magnetic Fields and Forces

EM Induction and Em Waves

AC Electricity

Relativity

Atoms and Molecules

Nuclear Physics

Filters

A laser pulse of duration 25 ms has a total energy of 1.4 J. If the wavelength of this radiation is 567 nm, how many photons are emitted in one pulse? (c = 3.00 × 10⁸ m/s, h = 6.626 × 10^-34 J ∙ s)

The work function of a particular metal is $4.20 \times 10 ^ { - 19 } \mathrm {~J}$ What is the photoelectric cutoff (threshold) wavelength for this metal? (c = 3.00 × 10⁸ m/s, h = 6.626 × 10^-34 J ∙ s)

Gamma rays are photons with very high energy. How many visible-light photons with a wavelength of 500 nm would you need to equal the energy of a gamma-ray photon with energy $4.1 \times 10 ^{- 13} \mathrm {~J} ?$

After an electron has been accelerated through a potential difference of 0.15 kV, what is its de Broglie wavelength? (e = 1.60 × 10^-19 C, m_electron = 9.11 × 10^-31 kg, h = 6.626 × 10^-34 J ∙ s)

The work function of a certain metal is 1.90 eV. What is the longest wavelength of light that can cause photoelectron emission from this metal? (1 eV = 1.60 × 10^-19 J, c = 3.00 × 10⁸ m/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 threshold (cutoff) frequency of this metal? (c = 3.00 × 10⁸ m/s, h = 6.626 × 10^-34 J ∙ s, 1 eV = 1.60 × 10^-19 J)

When it is struck by 240-nm photons, a material having a work function of 2.60 eV emits electrons. What is the maximum kinetic energy of the emitted electrons? (c = 3.00 × 10⁸ m/s, h = 6.626 × 10^-34 J ∙ s, 1 eV = 1.60 × 10^-19 J)

A proton and an electron are both accelerated to the same final speed. If λ_p is the de Broglie wavelength of the proton and λ_e is the de Broglie wavelength of the electron, then

Calculate the kinetic energy, in electron-volts, of a neutron that has a de Broglie wavelength of $7.2 \times 10 ^{- 12 }\mathrm {~m}$ (m_neutron = 1.675 × 10^-27 kg, 1 eV = 1.6 × 10^-19 J, h = 6.626 × 10^-34J ∙ s)

If the longest wavelength of light that is able to dislodge electrons from a metal is 373 nm, what is the work function of that metal, in electron-volts? (1 eV = 1.60 × 10^-19 J, c = 3.00 × 10⁸ m/s, h = 6.626 × 10^-34 J ∙ s)

How "slow" must a 200-g ball move to have a de Broglie wavelength of 1.0 mm? (h = 6.626 × 10^-34 J ∙ s)

Electrons with a speed of 2.1 × 10⁶ m/s are directed towards a 1.0-μm wide slit. An electron detector is placed 1.0 m behind the slit. How wide is the central maximum of the electron diffraction pattern on the detector? (h = 6.626 × 10^-34 J ∙ s, m_electron = 9.11 × 10^-31 kg)

What is the wavelength of the matter wave associated with an electron moving with a speed of 2.5 × 10⁷ m/s? (m_electron = 9.11 × 10^-31 kg, 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 measured to be 0.500 V. What is the work function of this metal? (c = 3.00 × 10⁸ m/s, h = 6.626 × 10^-34 J ∙ s, 1 eV = 1.60 × 10^-19 J)