Question 1

Evidence for the wave nature of matter is:

Accepted Answer

A) electron diffraction experiments of Davisson and Germer 
B) Thompson's measurement of e/m 
C) Young's double slit experiment 
D) the Compton effect 
E) Lenz's law 
A) electron diffraction experiments of Davisson and Germer 
B) Thompson's measurement of e/m 
C) Young's double slit experiment 
D) the Compton effect 
E) Lenz's law

Question 2

In Compton scattering from stationary particles the maximum change in wavelength can be made smaller by using:

Accepted Answer

A) higher frequency radiation 
B) lower frequency radiation 
C) more massive particles 
D) less massive particles 
E) particles with greater charge 
A) higher frequency radiation 
B) lower frequency radiation 
C) more massive particles 
D) less massive particles 
E) particles with greater charge

Question 3

An electron with energy E is incident upon a potential energy barrier of height Epot > E and thickness L.The transmission coefficient T:

Accepted Answer

A) is zero 
B) decreases exponentially with L 
C) is proportional to 1/L 
D) is proportional to 1/L2 
E) is non-zero and independent of L 
A) is zero 
B) decreases exponentially with L 
C) is proportional to 1/L 
D) is proportional to 1/L2 
E) is non-zero and independent of L

Question 4

The frequency and wavelength of the matter wave associated with a 10-eV free electron are:

Accepted Answer

A) 1.5* 1034 Hz, 3.9 * 10-10 m 
B) 1.5 * 1034 Hz, 1.3 *10-34 m 
C) 2.4 *1015 Hz, 1.2 * 10-9 m 
D) 2.4*1015 Hz, 3.9 *10-10 m 
E) 4.8 *1015 Hz, 1.9 * 10-10 m 
A) 1.5* 1034 Hz, 3.9 * 10-10 m 
B) 1.5 * 1034 Hz, 1.3 *10-34 m 
C) 2.4 *1015 Hz, 1.2 * 10-9 m 
D) 2.4*1015 Hz, 3.9 *10-10 m 
E) 4.8 *1015 Hz, 1.9 * 10-10 m

Question 5

An electron with energy E is incident upon a potential energy barrier of height Epot < E and thickness L.If the reflection coefficient R = 0.05,

Accepted Answer

A) the electron has a 0.05% chance of being reflected 
B) the electron has a 5% chance of being reflected 
C) the electron has a 95% chance of being reflected 
D) the electron will be partially reflected and partially transmitted 
E) the electron has no chance of being reflected 
A) the electron has a 0.05% chance of being reflected 
B) the electron has a 5% chance of being reflected 
C) the electron has a 95% chance of being reflected 
D) the electron will be partially reflected and partially transmitted 
E) the electron has no chance of being reflected

Question 6

The work function for a certain sample is 2.3 eV.The stopping potential for electrons ejected from the sample by 7.0 * 1014-Hz electromagnetic radiation is:

Accepted Answer

A) 0 V 
B) 0.60 V 
C) 2.3 V 
D) 2.9 V 
E) 5.2 V 
A) 0 V 
B) 0.60 V 
C) 2.3 V 
D) 2.9 V 
E) 5.2 V

Question 7

The stopping potential for electrons ejected by 6.8 * 1014-Hz electromagnetic radiation incident on a certain sample is 1.8 V.The kinetic energy of the most energetic electrons ejected and the work function of the sample, respectively, are:

Accepted Answer

A) 1.8 eV, 2.8 eV 
B) 1.8 eV, 1.0 eV 
C) 1.8 eV, 4.6 eV 
D) 2.8 eV, 1.0 eV 
E) 1.0 eV, 4.6 eV 
A) 1.8 eV, 2.8 eV 
B) 1.8 eV, 1.0 eV 
C) 1.8 eV, 4.6 eV 
D) 2.8 eV, 1.0 eV 
E) 1.0 eV, 4.6 eV

Question 8

Electromagnetic radiation with a wavelength of 5.7 * 10-12 m is incident on stationary electrons.Radiation that has a wavelength of 6.6 *10-12 m is detected at a scattering angle of:

Accepted Answer

A) 10° 
B) 40° 
C) 50° 
D) 69° 
E) 111° 
A) 10° 
B) 40° 
C) 50° 
D) 69° 
E) 111°

Question 9

In a photoelectric effect experiment at a frequency above cut off, the number of electrons ejected is proportional to:

Accepted Answer

A) their kinetic energy 
B) their potential energy 
C) the work function 
D) the frequency of the incident light 
E) the number of photons that hit the sample 
A) their kinetic energy 
B) their potential energy 
C) the work function 
D) the frequency of the incident light 
E) the number of photons that hit the sample

Question 10

A free electron and a free proton have the same kinetic energy.This means that, compared to the matter wave associated with the proton, the matter wave associated with the electron has:

Accepted Answer

A) a shorter wavelength and a greater frequency 
B) a longer wavelength and a greater frequency 
C) a shorter wavelength and the same frequency 
D) a longer wavelength and the same frequency 
E) a shorter wavelength and a smaller frequency 
A) a shorter wavelength and a greater frequency 
B) a longer wavelength and a greater frequency 
C) a shorter wavelength and the same frequency 
D) a longer wavelength and the same frequency 
E) a shorter wavelength and a smaller frequency

Question 11

The main problem that physicists had in understanding blackbody radiation before Planck's work was:

Accepted Answer

A) Blackbody radiation came from objects that were not actually black. 
B) The classically predicted frequency spectrum showed an infinitely large peak at low frequencies. 
C) The classically predicted frequency spectrum showed an infinitely large peak at high frequencies. 
D) The classically predicted frequency spectrum had a minimum intensity rather than a maximum as observed. 
E) The classically predicted frequency spectrum had a maximum intensity that decreased with temperature, rather than increasing as observed. 
A) Blackbody radiation came from objects that were not actually black. 
B) The classically predicted frequency spectrum showed an infinitely large peak at low frequencies. 
C) The classically predicted frequency spectrum showed an infinitely large peak at high frequencies. 
D) The classically predicted frequency spectrum had a minimum intensity rather than a maximum as observed. 
E) The classically predicted frequency spectrum had a maximum intensity that decreased with temperature, rather than increasing as observed.

Question 12

The uncertainty in position of an electron in a certain state is 5 * 10-10 m.The uncertainty in its momentum could be

Accepted Answer

A) 5.0 * 10-24 kg.m/s 
B) 4.0 * 10-24 kg.m/s 
C) 3.0* 10-24 kg.m/s 
D) any of the above 
E) none of the above 
A) 5.0 * 10-24 kg.m/s 
B) 4.0 * 10-24 kg.m/s 
C) 3.0* 10-24 kg.m/s 
D) any of the above 
E) none of the above

Question 13

Which of the following is NOT evidence for the wave nature of matter?

Accepted Answer

A) The photoelectric effect 
B) The diffraction pattern obtained when electrons pass through a slit 
C) Electron tunneling 
D) The validity of the Heisenberg uncertainty principle 
E) The interference pattern obtained when electrons pass through a two-slit system 
A) The photoelectric effect 
B) The diffraction pattern obtained when electrons pass through a slit 
C) Electron tunneling 
D) The validity of the Heisenberg uncertainty principle 
E) The interference pattern obtained when electrons pass through a two-slit system

Question 14

In Compton scattering from stationary electrons the frequency of the emitted light is independent of:

Accepted Answer

A) the frequency of the incident light 
B) the recoil speed of the electron 
C) the scattering angle 
D) the electron recoil energy 
E) none of the above 
A) the frequency of the incident light 
B) the recoil speed of the electron 
C) the scattering angle 
D) the electron recoil energy 
E) none of the above

Question 15

The main problem physicists had with understanding the photoelectric effect before Einstein explained it in terms of photons was:

Accepted Answer

A) the intensity of emitted electrons did not depend on the intensity of the source. 
B) the maximum energy of the emitted electrons did not depend on the frequency of the source. 
C) the maximum energy of the emitted electrons did not depend on the intensity of the source. 
D) the cutoff frequency depended on the material used as a target. 
E) the cutoff frequency did not depend on the material used as a target. 
A) the intensity of emitted electrons did not depend on the intensity of the source. 
B) the maximum energy of the emitted electrons did not depend on the frequency of the source. 
C) the maximum energy of the emitted electrons did not depend on the intensity of the source. 
D) the cutoff frequency depended on the material used as a target. 
E) the cutoff frequency did not depend on the material used as a target.

Question 16

Which of the following electromagnetic radiations has photons with the greatest momentum?

Accepted Answer

A) blue light 
B) yellow light 
C) x rays 
D) radio waves 
E) microwaves 
A) blue light 
B) yellow light 
C) x rays 
D) radio waves 
E) microwaves

Question 17

What is the temperature of a burner on an electric stove when its glow is barely visible, at a wavelength of 700 nm? Assume the burner radiates as an ideal blackbody and that 700 nm represents the peak of its emission spectrum.

Accepted Answer

A) 41 K 
B) 240 K 
C) 410 K 
D) 2400 K 
E) 4100 K 
A) 41 K 
B) 240 K 
C) 410 K 
D) 2400 K 
E) 4100 K

Question 18

Light beams A and B have the same intensity but the wavelength associated with beam A is longer than that associated with beam B.The photon flux (number crossing a unit area per unit time)is:

Accepted Answer

A) greater for A than for B 
B) greater for B than for A 
C) the same for A and B 
D) greater for A than for B only if both have short wavelengths 
E) greater for B than for A only if both have short wavelengths 
A) greater for A than for B 
B) greater for B than for A 
C) the same for A and B 
D) greater for A than for B only if both have short wavelengths 
E) greater for B than for A only if both have short wavelengths

Question 19

The concentration of photons in a uniform light beam with a wavelength of 500 nm is 1.7 *1013 m - 3.The intensity of the beam is:

Accepted Answer

A) 6.8 * 10 - 6 W/m2 
B) 3.2* 102 W/m2  
C) 1.0 * 103 W/m2 
D) 2.0 *103 W/m2 
E) 4.0 F*103 W/m2 
A) 6.8 * 10 - 6 W/m2 
B) 3.2* 102 W/m2  
C) 1.0 * 103 W/m2 
D) 2.0 *103 W/m2 
E) 4.0 F*103 W/m2

Exam 38: Photons and Matter Waves

Evidence for the wave nature of matter is:

In Compton scattering from stationary particles the maximum change in wavelength can be made smaller by using:

An electron with energy E is incident upon a potential energy barrier of height Epot > E and thickness L.The transmission coefficient T:

The frequency and wavelength of the matter wave associated with a 10-eV free electron are:

An electron with energy E is incident upon a potential energy barrier of height Epot < E and thickness L.If the reflection coefficient R = 0.05,

The work function for a certain sample is 2.3 eV.The stopping potential for electrons ejected from the sample by 7.0 * 1014-Hz electromagnetic radiation is:

The stopping potential for electrons ejected by 6.8 * 1014-Hz electromagnetic radiation incident on a certain sample is 1.8 V.The kinetic energy of the most energetic electrons ejected and the work function of the sample, respectively, are:

Electromagnetic radiation with a wavelength of 5.7 * 10-12 m is incident on stationary electrons.Radiation that has a wavelength of 6.6 *10-12 m is detected at a scattering angle of:

In a photoelectric effect experiment at a frequency above cut off, the number of electrons ejected is proportional to:

A free electron and a free proton have the same kinetic energy.This means that, compared to the matter wave associated with the proton, the matter wave associated with the electron has:

The main problem that physicists had in understanding blackbody radiation before Planck's work was:

The uncertainty in position of an electron in a certain state is 5 * 10-10 m.The uncertainty in its momentum could be

Which of the following is NOT evidence for the wave nature of matter?

In Compton scattering from stationary electrons the frequency of the emitted light is independent of:

The main problem physicists had with understanding the photoelectric effect before Einstein explained it in terms of photons was:

Which of the following electromagnetic radiations has photons with the greatest momentum?

What is the temperature of a burner on an electric stove when its glow is barely visible, at a wavelength of 700 nm? Assume the burner radiates as an ideal blackbody and that 700 nm represents the peak of its emission spectrum.

Light beams A and B have the same intensity but the wavelength associated with beam A is longer than that associated with beam B.The photon flux (number crossing a unit area per unit time)is:

The concentration of photons in a uniform light beam with a wavelength of 500 nm is 1.7 *1013 m - 3.The intensity of the beam is:

Measurement

Motion Along a Straight Line

Vectors

Motion in Two and Three Dimensions

Force and Motion

Force and Motion

Kinetic Energy and Work

Potential Energy and Conservation of Energy

Center of Mass and Linear Momentum

Rotation

Rolling, Torque, and Angular Momentum

Equilibrium and Elasticity

Gravitation

Fluids

Oscillations

Waves

Waves

Temperature, Heat, and the First Law of Thermodynamics

The Kinetic Theory of Gases

Entropy and the Second Law of Thermodynamics

Coulombs Law

Electric Fields

Gauss Law

Electric Potential

Capacitance

Current and Resistance

Circuits

Magnetic Fields

Magnetic Fields Due to Currents

Induction and Inductance

Electromagnetic Oscillations and Alternating Current

Maxwells Equations; Magnetism of Matter

Electromagnetic Waves

Images

Interference 1

Diffraction

Relativity

More About Matter Waves

All About Atoms

Conduction of Electricity in Solids

Energy From the Nucleus

Quarks, Leptons, and the Big Bang

Filters

An electron with energy E is incident upon a potential energy barrier of height E_pot > E and thickness L.The transmission coefficient T:

An electron with energy E is incident upon a potential energy barrier of height E_pot < E and thickness L.If the reflection coefficient R = 0.05,

The work function for a certain sample is 2.3 eV.The stopping potential for electrons ejected from the sample by 7.0 * 10¹⁴-Hz electromagnetic radiation is:

The stopping potential for electrons ejected by 6.8 * 10¹⁴-Hz electromagnetic radiation incident on a certain sample is 1.8 V.The kinetic energy of the most energetic electrons ejected and the work function of the sample, respectively, are:

Electromagnetic radiation with a wavelength of 5.7 * 10^-12 m is incident on stationary electrons.Radiation that has a wavelength of 6.6 *10^-12 m is detected at a scattering angle of:

The uncertainty in position of an electron in a certain state is 5 * 10^-10 m.The uncertainty in its momentum could be

The concentration of photons in a uniform light beam with a wavelength of 500 nm is 1.7 *10¹³ m ^- ³.The intensity of the beam is: