Question 1

If the wavelength of a photon is doubled,what happens to its energy?

Accepted Answer

A) It is reduced to one-half of its original value. 
B) It stays the same. 
C) It is doubled. 
D) It is increased to four times its original value. 
E) It is reduced to one-fourth of its original value. 
A) It is reduced to one-half of its original value. 
B) It stays the same. 
C) It is doubled. 
D) It is increased to four times its original value. 
E) It is reduced to one-fourth of its original value.

Question 2

When a photoelectric surface is illuminated with light of wavelength 437 nm,the stopping potential is measured to be 1.67 V.(1 eV = 1.60 × 10-19 J,e = 1.60 × 10-19 C,melectron = 9.11 × 10-31 kg,h = 6.626 × 10-34 J ∙ s)
(a)What is the work function of the metal,in eV?
(b)What is the maximum speed of the ejected electrons?

Accepted Answer

(a)1.17 eV

Question 3

An x-ray tube accelerates electrons through a potential difference of 50.0 kV.If an electron in the beam suddenly give up its kinetic energy in a collision,what is the shortest wavelength x-ray it could produce? (c = 3.00 × 108 m/s,h = 6.626 × 10-34 J ∙ s,e = 1.60 × 10-19
C)

Accepted Answer

Question 4

Monochromatic light falls on a metal surface and electrons are ejected.If the intensity of the light is increased,what will happen to the ejection rate and maximum energy of the electrons?

Accepted Answer

A) greater rate; same maximum energy. 
B) same rate; greater maximum energy. 
C) greater rate; greater maximum energy. 
D) same rate; same maximum energy. 
A) greater rate; same maximum energy. 
B) same rate; greater maximum energy. 
C) greater rate; greater maximum energy. 
D) same rate; same maximum energy.

Question 5

If the scattering angle of the light in Compton's scattering experiment is 90°,what is the change in the wavelength of the light? (melectron = 9.11 × 10-31 kg,c = 3.00 × 108 m/s,h = 6.626 × 10-34 J ∙ s)

Accepted Answer

A) 1.22 × 10-12 m 
B) 2.42 × 10-12 m 
C) 3.65 × 10-12 m 
D) 4.85 × 10-12 m 
A) 1.22 × 10-12 m 
B) 2.42 × 10-12 m 
C) 3.65 × 10-12 m 
D) 4.85 × 10-12 m

Question 6

By what primary heat transfer mechanism does the sun warm the earth?

Accepted Answer

A) convection 
B) conduction 
C) radiation 
D) All of the above processes are equally important in combination. 
A) convection 
B) conduction 
C) radiation 
D) All of the above processes are equally important in combination.

Question 7

A blue laser beam is incident on a metallic surface,causing electrons to be ejected from the metal.If the frequency of the laser beam is increased while the intensity of the beam is held fixed,

Accepted Answer

A) the rate of ejected electrons will decrease and their maximum kinetic energy will increase. 
B) the rate of ejected electrons will remain the same but their maximum kinetic energy will increase. 
C) the rate of ejected electrons will increase and their maximum kinetic energy will increase. 
D) the rate of ejected electrons will remain the same but their maximum kinetic energy will decrease. 
A) the rate of ejected electrons will decrease and their maximum kinetic energy will increase. 
B) the rate of ejected electrons will remain the same but their maximum kinetic energy will increase. 
C) the rate of ejected electrons will increase and their maximum kinetic energy will increase. 
D) the rate of ejected electrons will remain the same but their maximum kinetic energy will decrease.

Question 8

In her physics laboratory,Mathilda shines electromagnetic radiation on a material and collects photoelectric data to determine Planck's constant.She measures a stopping potential of 5.82 V for radiation of wavelength 100 nm,and 17.99 V for radiation of wavelength 50.0 nm.(1 eV = 1.60 × 10-19 J,c = 3.00 × 108 m/s)
(a)Using Mathilda's data,what value does she determine for Planck's constant?
(b)What is the work function of the material Mathilda is using,in electron-volts?

Accepted Answer

(a)6.49 ×

Question 9

The cosmic background radiation permeating the universe has the spectrum of a 2.7-K blackbody radiator.What is the peak wavelength of this radiation? The constant in Wien's law is 0.0029 m ∙ K.

Accepted Answer

1.1 mm (mi

Question 10

If the wavelength of a photon is the same as the de Broglie wavelength of an electron,which one has the greater momentum?

Accepted Answer

A) The electron because it has more mass. 
B) The photon because it is traveling faster. 
C) They both have the same momentum. 
A) The electron because it has more mass. 
B) The photon because it is traveling faster. 
C) They both have the same momentum.

Question 11

A laser emits a pulse of light that lasts 10 ns.The light has a wavelength of 690 nm,and each pulse has an energy of 480 mJ.How many photons are emitted in each pulse? (c = 3.0 × 108 m/s,h = 6.626 × 10-34 J ∙ s)

Accepted Answer

A) 1.7 × 1018 
B) 2.1 × $10^{27}$ 
C) 2.6 × $10^{37}$ 
D) 3.1 × $10^{43}$ 
A) 1.7 × 1018 
B) 2.1 × $10^{27}$ 
C) 2.6 × $10^{37}$ 
D) 3.1 × $10^{43}$

Question 12

A photocathode whose work function is 2.9 eV is illuminated with white light that has a continuous wavelength band from 400 nm to 700 nm.What is the range of the wavelength band in this white light illumination for which photoelectrons are not produced?(c = 3.00 × 108 m/s,h = 6.626 × 10-34 J ∙ s,1 eV = 1.60 × 10-19 J)

Accepted Answer

A) 430 nm to 700 nm 
B) 400 nm to 480 nm 
C) 430 nm to 480 nm 
D) 400 nm to 430 nm 
E) 480 nm to 700 nm 
A) 430 nm to 700 nm 
B) 400 nm to 480 nm 
C) 430 nm to 480 nm 
D) 400 nm to 430 nm 
E) 480 nm to 700 nm

Question 13

As the temperature of a blackbody increases,what happens to the peak wavelength of the light it radiates?

Accepted Answer

A) It gets longer. 
B) It gets shorter. 
C) The wavelength is not affected by the temperature of the object. 
A) It gets longer. 
B) It gets shorter. 
C) The wavelength is not affected by the temperature of the object.

Question 14

A 140-keV photon strikes an electron and scatters through an angle of 120° from its original direction.(melectron = 9.11 × 10-31 kg,c = 3.00 × 108 m/s,h = 6.626 × 10-34 J ∙ s)
(a)What is the wavelength of the photon before scattering?
(b)What is the photon wavelength after scattering?

Accepted Answer

(a)8.87 pm

Question 15

If the wavelength of a light beam is doubled,what happens to the momentum of the photons in that light beam?

Accepted Answer

A) It is halved. 
B) It stays the same. 
C) It is doubled. 
D) It is reduced by one-fourth of its original value. 
E) It is increased to four times its original value. 
A) It is halved. 
B) It stays the same. 
C) It is doubled. 
D) It is reduced by one-fourth of its original value. 
E) It is increased to four times its original value.

Question 16

In a Compton scattering experiment using x-rays,the wavelength of the x-rays increases by 5.0% as the light is scattered at an angle of 60° with its original direction.What was the original wavelength of the light before scattering? (melectron = 9.11 × 10-31 kg,c = 3.00 × 108 m/s,h = 6.626 × 10-34 J ∙ s)

Accepted Answer

Question 17

Increasing the brightness of a beam of light without changing its color will increase

Accepted Answer

A) the number of photons per second traveling in the beam. 
B) the energy of each photon. 
C) the speed of the photons. 
D) the frequency of the light. 
E) the wavelength of the photons. 
A) the number of photons per second traveling in the beam. 
B) the energy of each photon. 
C) the speed of the photons. 
D) the frequency of the light. 
E) the wavelength of the photons.

Question 18

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)

Accepted Answer

A) 4.0 × 1018 
B) 9.9 × 1019 
C) 4.8 × 1019 
D) 1.6 × 1017 
E) 3.2 × 1017 
A) 4.0 × 1018 
B) 9.9 × 1019 
C) 4.8 × 1019 
D) 1.6 × 1017 
E) 3.2 × 1017

Question 19

If you double the frequency of the light in a laser beam,but keep the number of photons per second in the beam fixed,which of the following statements are correct? (There could be more than one correct choice.)

Accepted Answer

A) The power in the beam does not change. 
B) The intensity of the beam doubles. 
C) The energy of individual photons does not change. 
D) The energy of individual photons doubles. 
E) The wavelength of the individual photons doubles. 
A) The power in the beam does not change. 
B) The intensity of the beam doubles. 
C) The energy of individual photons does not change. 
D) The energy of individual photons doubles. 
E) The wavelength of the individual photons doubles.

Question 20

A certain photon,after being scattered from a free electron that was at rest,moves at an angle of 120° with respect to the incident direction.If the wavelength of the incident photon is 0.591 nm, what is the energy of the scattered photon? $\left( m _ { \text {electron } } = 9.11 \times 10 ^ { - 31 } \mathrm {~kg} , \right.$ $c = 3.00 \times 10^8 \mathrm {~m} / \mathrm { s }$ $\left. h = 6.626 \times 10 ^ { - 34 } \mathrm {~J} \cdot \mathrm { s } \right)$

Accepted Answer

A) 1.05 × $10 ^{- 16}$ J 
B) 2.10 × $10 ^{- 16}$
 J 
C) 5.71 × $10 ^{- 16}$
 J 
D) 3.34 × $10 ^{- 16}$
 J 
E) 4.21 × $10 ^{- 16}$
 J 
A) 1.05 × $10 ^{- 16}$ J 
B) 2.10 × $10 ^{- 16}$
 J 
C) 5.71 × $10 ^{- 16}$
 J 
D) 3.34 × $10 ^{- 16}$
 J 
E) 4.21 × $10 ^{- 16}$
 J

Exam 27: Quantum Optics

If the wavelength of a photon is doubled,what happens to its energy?

An x-ray tube accelerates electrons through a potential difference of 50.0 kV.If an electron in the beam suddenly give up its kinetic energy in a collision,what is the shortest wavelength x-ray it could produce? (c = 3.00 × 108 m/s,h = 6.626 × 10-34 J ∙ s,e = 1.60 × 10-19 C)

Monochromatic light falls on a metal surface and electrons are ejected.If the intensity of the light is increased,what will happen to the ejection rate and maximum energy of the electrons?

If the scattering angle of the light in Compton's scattering experiment is 90°,what is the change in the wavelength of the light? (melectron = 9.11 × 10-31 kg,c = 3.00 × 108 m/s,h = 6.626 × 10-34 J ∙ s)

By what primary heat transfer mechanism does the sun warm the earth?

A blue laser beam is incident on a metallic surface,causing electrons to be ejected from the metal.If the frequency of the laser beam is increased while the intensity of the beam is held fixed,

The cosmic background radiation permeating the universe has the spectrum of a 2.7-K blackbody radiator.What is the peak wavelength of this radiation? The constant in Wien's law is 0.0029 m ∙ K.

If the wavelength of a photon is the same as the de Broglie wavelength of an electron,which one has the greater momentum?

A laser emits a pulse of light that lasts 10 ns.The light has a wavelength of 690 nm,and each pulse has an energy of 480 mJ.How many photons are emitted in each pulse? (c = 3.0 × 108 m/s,h = 6.626 × 10-34 J ∙ s)

As the temperature of a blackbody increases,what happens to the peak wavelength of the light it radiates?

A 140-keV photon strikes an electron and scatters through an angle of 120° from its original direction.(melectron = 9.11 × 10-31 kg,c = 3.00 × 108 m/s,h = 6.626 × 10-34 J ∙ s) (a)What is the wavelength of the photon before scattering? (b)What is the photon wavelength after scattering?

If the wavelength of a light beam is doubled,what happens to the momentum of the photons in that light beam?

Increasing the brightness of a beam of light without changing its color will increase

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)

If you double the frequency of the light in a laser beam,but keep the number of photons per second in the beam fixed,which of the following statements are correct? (There could be more than one correct choice.)

Introduction

Kinematics: Motion in One Dimension

Newtonian Mechanics

Applying Newtons Laws

Circular Motion

Impulse and Linear Momentum

Work and Energy

Extended Bodies at Rest

Rotational Motion

Gases

Static Fluids

Fluids in Motion

First Law of Thermodynamics

Second Law of Thermodynamics

Electric Charge force and Energy

The Electric Field

Dc Circuits

Magnetism

Electromagnetic Induction

Vibrational Motion

Mechanical Waves

Reflection and Refraction

Mirrors and Lenses

Wave Optics

Electromagnetic Waves

Special Relativity

Atomic Physics

Nuclear Physics

Particle Physics

Filters

An x-ray tube accelerates electrons through a potential difference of 50.0 kV.If an electron in the beam suddenly give up its kinetic energy in a collision,what is the shortest wavelength x-ray it could produce? (c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s,e = 1.60 × 10^-19 C)

If the scattering angle of the light in Compton's scattering experiment is 90°,what is the change in the wavelength of the light? (m_electron = 9.11 × 10^-31 kg,c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

A laser emits a pulse of light that lasts 10 ns.The light has a wavelength of 690 nm,and each pulse has an energy of 480 mJ.How many photons are emitted in each pulse? (c = 3.0 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

A 140-keV photon strikes an electron and scatters through an angle of 120° from its original direction.(m_electron = 9.11 × 10^-31 kg,c = 3.00 × 10⁸ m/s,h = 6.626 × 10-34 J ∙ s) (a)What is the wavelength of the photon before scattering? (b)What is the photon wavelength after scattering?

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)