Question 1

The frequencies of the normal modes of a string that is free at both ends are the same as those of a string that is fixed at both ends.

Accepted Answer

A) True 
 B)False

Question 2

The period $T$ of the fundamental mode of the air in a pipe open at one end and closed at the other is equal to what multiple or fraction of the time $\Delta t$ required for a sound wave to travel from one end of the tube to the other?

Accepted Answer

A)  $T=\Delta t / 4$ 
B)  $T=\Delta t / 2$ 
C)  $T=\Delta t$ 
D)  $T=2 \Delta t$ 
E)  $T=4 \Delta t$ 
A)  $T=\Delta t / 4$ 
B)  $T=\Delta t / 2$ 
C)  $T=\Delta t$ 
D)  $T=2 \Delta t$ 
E)  $T=4 \Delta t$

Question 3

${ }_{94}^{232} \mathrm{Pu}$ is unstable. Which of the following nuclei might be a possible outcome of a single-step decay process from this nucleus? (Hints: The optimal NIZ ratio for this $A$ is about 1.53. This nucleus has two possible decay outcomes, but perhaps only one is listed. If you are using the back of the book to respond, you can indicate multiple responses by pointing to more than one letter.)

Accepted Answer

A)  ${ }_{90}^{230} \mathrm{Th}$ 
B)  ${ }_{92}^{230} \mathrm{U}$ 
C)  ${ }_{92}^{228} \mathbf{U}$ 
D)  ${ }_{95}^{232} \mathrm{Am}$ 
E)  ${ }_{95}^{231} \mathrm{Am}$
F) None of the above (specify an outcome) 
A)  ${ }_{90}^{230} \mathrm{Th}$ 
B)  ${ }_{92}^{230} \mathrm{U}$ 
C)  ${ }_{92}^{228} \mathbf{U}$ 
D)  ${ }_{95}^{232} \mathrm{Am}$ 
E)  ${ }_{95}^{231} \mathrm{Am}$
F) None of the above (specify an outcome)

Question 4

Suppose that at time $t=0$ an electron in a magnetic field in the $+z$ direction has state $|\psi(0)\rangle=|+x\rangle$. Let $\omega=\left[E_{+}-E_{-}\right] / \hbar$.
-(b) The expectation value $\left\langle s_{x}\right\rangle$ as a function of time in this case is which of the below?

Accepted Answer

A)  $+\frac{1}{2} \hbar$ 
B)  $-\frac{1}{2} \hbar$ 
C)  0 
D)  $+\frac{1}{2} \hbar \cos \omega t$ 
E)  $+\frac{1}{2} \hbar \sin \omega t$
F) Something else (specify) 
A)  $+\frac{1}{2} \hbar$ 
B)  $-\frac{1}{2} \hbar$ 
C)  0 
D)  $+\frac{1}{2} \hbar \cos \omega t$ 
E)  $+\frac{1}{2} \hbar \sin \omega t$
F) Something else (specify)

Question 5

Combining any two nuclei should release energy, because doing this increases the number of strong inter nuclear bonds between nucleons.

Accepted Answer

A) True 
 B)False

Question 6

What, according to the chapter, is the essence of the paradox in Schrödinger's cat paradox?

Accepted Answer

A)  Opening the box (and thus observing the cat) might kill it, contrary to our experience of reality. 
B)  The cat, though it should be described by quantum mechanics, never displays the features of a superposition state, like microscopic systems do. 
C)  The cat being alive or being dead are not mutually exclusive possibilities, contrary to what we think. 
D)  Human consciousness is necessary to collapse the cat's state to being alive or dead. 
E)  Something else (explain). 
A)  Opening the box (and thus observing the cat) might kill it, contrary to our experience of reality. 
B)  The cat, though it should be described by quantum mechanics, never displays the features of a superposition state, like microscopic systems do. 
C)  The cat being alive or being dead are not mutually exclusive possibilities, contrary to what we think. 
D)  Human consciousness is necessary to collapse the cat's state to being alive or dead. 
E)  Something else (explain).

Question 7

A radioactive sample's activity $A$ at a given time is directly proportional to the number of nuclei that have already decayed.

Accepted Answer

A) True 
 B)False

Question 8

Which of the following nuclei has the greatest binding energy per nucleon?

Accepted Answer

A)  ${ }_{2}^{4} \mathrm{He}$ 
B)  ${ }_{6}^{12} \mathrm{C}$ 
C)  ${ }_{10}^{20} \mathrm{Ne}$ 
D)  ${ }_{26}^{56} \mathrm{Fe}$ 
E)  ${ }_{82}^{207} \mathrm{~Pb}$
F) ${ }_{92}^{235} \mathrm{U}$ 
A)  ${ }_{2}^{4} \mathrm{He}$ 
B)  ${ }_{6}^{12} \mathrm{C}$ 
C)  ${ }_{10}^{20} \mathrm{Ne}$ 
D)  ${ }_{26}^{56} \mathrm{Fe}$ 
E)  ${ }_{82}^{207} \mathrm{~Pb}$
F) ${ }_{92}^{235} \mathrm{U}$

Question 9

The ${ }_{13}^{26}$ Al nucleus is unstable. To what will it decay? (Hint: Electrostatic repulsion is a significant effect here.)

Accepted Answer

A)  ${ }_{14}^{26} \mathrm{Si}+e^{-}+\bar{v}$ 
B)  ${ }_{14}^{25} \mathrm{Si}+e^{-}+\bar{v}$ 
C)  ${ }_{12}^{26} \mathrm{Mg}+\mathrm{e}^{-}+\bar{v}$ 
D)  ${ }_{12}^{26} \mathbf{M g}+\boldsymbol{e}^{+}+\boldsymbol{v}$ 
E)  Other (specify) 
A)  ${ }_{14}^{26} \mathrm{Si}+e^{-}+\bar{v}$ 
B)  ${ }_{14}^{25} \mathrm{Si}+e^{-}+\bar{v}$ 
C)  ${ }_{12}^{26} \mathrm{Mg}+\mathrm{e}^{-}+\bar{v}$ 
D)  ${ }_{12}^{26} \mathbf{M g}+\boldsymbol{e}^{+}+\boldsymbol{v}$ 
E)  Other (specify)

Question 10

Consider the experimental evidence we have discussed in the past few chapters. Classify the following experimental results according to the following scheme: For the quantons in question, the results:
-The maximum kinetic energy of electrons ejected from a metal surface depends on the frequency of the light shining on the surface, and not on the intensity.

Accepted Answer

The answer of Consider the experimental evidence we have discussed...

Question 11

The Quantum Zeno effect shows that determining a quanton's state often enough can prevent its evolution as predicted by the Time Evolution Rule.

Accepted Answer

A) True 
 B)False

Question 12

Weak-interaction processes conserve both electric charge and a quantity called "lepton number." Electrons have lepton number $=+1$, positrons have lepton number -1 , and nucleons have lepton number $=0$. Study the weak interactions in this chapter.
-(b) What can you infer about the lepton number of the anti-neutrino?

Accepted Answer

A)  This quanton has lepton number $=+1$. 
B)  This quanton has lepton number $\mathbf{=} \mathbf{- 1}$. 
C)  This quanton has lepton number $=0$. 
D)  One cannot determine this quanton's lepton number from the processes we have studied. 
A)  This quanton has lepton number $=+1$. 
B)  This quanton has lepton number $\mathbf{=} \mathbf{- 1}$. 
C)  This quanton has lepton number $=0$. 
D)  One cannot determine this quanton's lepton number from the processes we have studied.

Question 13

The mass of the earth-moon system is somewhat less than the sum of the mass of the earth and the mass of the moon.

Accepted Answer

A) True 
 B)False

Question 14

Suppose that at a certain instant of time, the wave function shown below describes a certain quanton's state. If we were to perform an experiment to locate the quanton, what would be the least likely result or results within the graph's range?

Accepted Answer

A)  $x_{A}$ 
B)  $x_{B}$ and $x_{C}$ 
C)  $x=0$ 
D)  $x_{D}$ 
A)  $x_{A}$ 
B)  $x_{B}$ and $x_{C}$ 
C)  $x=0$ 
D)  $x_{D}$

Question 15

A long-wavelength photon, because it is larger, carries more total energy than a short-wavelength photon.

Accepted Answer

A) True 
 B)False

Question 16

Consider the two time-dependent spin state vectors shown below:
$$\begin{aligned}
& \left|\psi_{A}\right\rangle=\sqrt{1 / 2}|+z\rangle-\sqrt{1 / 2} e^{-i E t / \hbar}|+z\rangle \
& \left|\psi_{B}\right\rangle=\sqrt{1 / 2} e^{+i E t / 2 \hbar}|+z\rangle-\sqrt{1 / 2} e^{-i E t / 2 \hbar}|+z\rangle
\end{aligned}$$
These state vectors are physically equivalent.

Accepted Answer

A) True 
 B)False

Question 17

Suppose the lowest band in a certain crystal is completely filled, but the gap between that band and the next higher one is $0.53 \mathrm{eV}$. What type of material is this?

Accepted Answer

A)  A conductor 
B)  An insulator 
C)  A semiconductor 
A)  A conductor 
B)  An insulator 
C)  A semiconductor

Question 18

In an experiment involving the apparatus shown in figure Q4.1b, suppose that after shining light on the cathode long enough that the voltmeter settles down to a fixed value, we suddenly cut off the light. If the voltmeter is truly ideal, what happens to the value displayed?

Accepted Answer

A)  It immediately drops to zero. 
B)  It slowly decays to zero. 
C)  It remains fixed. 
D)  It does something else. (Describe what.) 
A)  It immediately drops to zero. 
B)  It slowly decays to zero. 
C)  It remains fixed. 
D)  It does something else. (Describe what.)

Question 19

Which of the following events is most likely to directly cause a meltdown in a nuclear fission reactor?

Accepted Answer

A)  The fuel rods become old and brittle. 
B)  The reactor is operated at too high a power. 
C)  The chain reaction slowly starts to get out of control. 
D)  Pumps that circulate water in the reactor fail. 
E)  Either B or C. 
A)  The fuel rods become old and brittle. 
B)  The reactor is operated at too high a power. 
C)  The chain reaction slowly starts to get out of control. 
D)  Pumps that circulate water in the reactor fail. 
E)  Either B or C.

Question 20

In a cyanine dye molecule, one electron is free to move up and down along a linear chain of carbon atoms, but cannot pass the nitrogen atoms at each of the chain's ends. Assume that the length of the chain does not change much as we increase the electron's energy (within reasonable limits). Which of the idealized models in this chapter might best describe the electron in this situation?

Accepted Answer

A)  The quanton in a box model} 
B)  The Bohr model 
C)  The simple harmonic oscillator model 
A)  The quanton in a box model} 
B)  The Bohr model 
C)  The simple harmonic oscillator model

The frequencies of the normal modes of a string that is free at both ends are the same as those of a string that is fixed at both ends.

The period $T$ of the fundamental mode of the air in a pipe open at one end and closed at the other is equal to what multiple or fraction of the time $\Delta t$ required for a sound wave to travel from one end of the tube to the other?

Suppose that at time $t=0$ an electron in a magnetic field in the $+z$ direction has state $|\psi(0)\rangle=|+x\rangle$ . Let $\omega=\left[E_{+}-E_{-}\right] / \hbar$ . -(b) The expectation value $\left\langle s_{x}\right\rangle$ as a function of time in this case is which of the below?

Combining any two nuclei should release energy, because doing this increases the number of strong inter nuclear bonds between nucleons.

What, according to the chapter, is the essence of the paradox in Schrödinger's cat paradox?

A radioactive sample's activity $A$ at a given time is directly proportional to the number of nuclei that have already decayed.

Which of the following nuclei has the greatest binding energy per nucleon?

The ${ }_{13}^{26}$ Al nucleus is unstable. To what will it decay? (Hint: Electrostatic repulsion is a significant effect here.)

The Quantum Zeno effect shows that determining a quanton's state often enough can prevent its evolution as predicted by the Time Evolution Rule.

The mass of the earth-moon system is somewhat less than the sum of the mass of the earth and the mass of the moon.

Suppose that at a certain instant of time, the wave function shown below describes a certain quanton's state. If we were to perform an experiment to locate the quanton, what would be the least likely result or results within the graph's range?

A long-wavelength photon, because it is larger, carries more total energy than a short-wavelength photon.

Consider the two time-dependent spin state vectors shown below: =|+z\rangle-|+z\rangle =|+z\rangle-|+z\rangle These state vectors are physically equivalent.

Suppose the lowest band in a certain crystal is completely filled, but the gap between that band and the next higher one is $0.53 \mathrm{eV}$ . What type of material is this?

In an experiment involving the apparatus shown in figure Q4.1b, suppose that after shining light on the cathode long enough that the voltmeter settles down to a fixed value, we suddenly cut off the light. If the voltmeter is truly ideal, what happens to the value displayed?

Which of the following events is most likely to directly cause a meltdown in a nuclear fission reactor?

Conservation Laws Constrain Interactions

The Laws of Physics Are Universal Newtonian Mechanics

The Laws of Physics Are Frame-Independent Relativity

Electricity and Magnetism Are Unified

Some Processes Are Irreversible Thermal Physics

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Exam 5: Matter Behaves Like Waves Quantum Physics

The frequencies of the normal modes of a string that is free at both ends are the same as those of a string that is fixed at both ends.

The period TTT of the fundamental mode of the air in a pipe open at one end and closed at the other is equal to what multiple or fraction of the time Δt\Delta tΔt required for a sound wave to travel from one end of the tube to the other?

Combining any two nuclei should release energy, because doing this increases the number of strong inter nuclear bonds between nucleons.

What, according to the chapter, is the essence of the paradox in Schrödinger's cat paradox?

A radioactive sample's activity AAA at a given time is directly proportional to the number of nuclei that have already decayed.

Which of the following nuclei has the greatest binding energy per nucleon?

The 1326{ }_{13}^{26}1326​ Al nucleus is unstable. To what will it decay? (Hint: Electrostatic repulsion is a significant effect here.)

The Quantum Zeno effect shows that determining a quanton's state often enough can prevent its evolution as predicted by the Time Evolution Rule.

The mass of the earth-moon system is somewhat less than the sum of the mass of the earth and the mass of the moon.

Suppose that at a certain instant of time, the wave function shown below describes a certain quanton's state. If we were to perform an experiment to locate the quanton, what would be the least likely result or results within the graph's range?

A long-wavelength photon, because it is larger, carries more total energy than a short-wavelength photon.

Consider the two time-dependent spin state vectors shown below: =|+z\rangle-|+z\rangle =|+z\rangle-|+z\rangle These state vectors are physically equivalent.

Suppose the lowest band in a certain crystal is completely filled, but the gap between that band and the next higher one is 0.53eV0.53 \mathrm{eV}0.53eV . What type of material is this?

In an experiment involving the apparatus shown in figure Q4.1b, suppose that after shining light on the cathode long enough that the voltmeter settles down to a fixed value, we suddenly cut off the light. If the voltmeter is truly ideal, what happens to the value displayed?

Which of the following events is most likely to directly cause a meltdown in a nuclear fission reactor?

Conservation Laws Constrain Interactions

The Laws of Physics Are Universal Newtonian Mechanics

The Laws of Physics Are Frame-Independent Relativity

Electricity and Magnetism Are Unified

Some Processes Are Irreversible Thermal Physics

Filters

The period $T$ of the fundamental mode of the air in a pipe open at one end and closed at the other is equal to what multiple or fraction of the time $\Delta t$ required for a sound wave to travel from one end of the tube to the other?

A radioactive sample's activity $A$ at a given time is directly proportional to the number of nuclei that have already decayed.

The ${ }_{13}^{26}$ Al nucleus is unstable. To what will it decay? (Hint: Electrostatic repulsion is a significant effect here.)

Suppose the lowest band in a certain crystal is completely filled, but the gap between that band and the next higher one is $0.53 \mathrm{eV}$ . What type of material is this?