Question 1

On a bright and sunny day,the intensity of solar radiation on the Earth's surface is 1 000 W/m².If the average wavelength of the sunlight is 500 nm,how many photons are incident on a square meter of the Earth's surface per second?

Accepted Answer

2.51 * 10²¹ photons/s

Question 2

The threshold wavelength for photoelectric emission of a particular substance is 500 nm.What is the work function (in eV)?

Accepted Answer

A)  4.2
B)  4.0 *10 - 19
C)  4.0 *10 - 10
D)  2.5 *10 - 19
E)  2.5 E

Question 3

Your temperature is 98.6$\degree$F.Assuming your skin is a perfect radiator ($\varepsilon$ = 1),determine the wavelength corresponding to the largest intensity (in $\mu$m).

Accepted Answer

A)  8.0
B)  9.3
C)  3.0
D)  5.7
E)  29.4  B

Question 4

A baseball (1 kg)has an energy of 100 joules.If its uncertainty in position is 1 m,what is the percentage uncertainty ($\Delta$p/p * 100)in the momentum of the baseball?

Accepted Answer

A)  
B)  1%
C)  2%
D)  5%
E)  10%

Question 5

A particle is in the first excited state of a one-dimensional box of length 1.0 m.What is the minimum value of its momentum (in kg . m/s)?

Accepted Answer

A)  3.3 *10 - 34
B)  6.6 *10 - 34
C)  9.9 *10 - 34
D)  13 *10 - 34
E)  22 *10 - 34

Question 6

An electron is accelerated through a potential difference of 25 000 V.What is the de Broglie wavelength of the electron (in m)?

Accepted Answer

A)  5.9 *10 - 12
B)  6.8 *10 - 12
C)  6.5*10 - 12
D)  7.8 *10 - 12
E)  5.5 *10 - 12

Question 7

A neutron has a mass of 1.67 *10 - 27 kg.Its de Broglie wavelength is 1.4 *10 - 10 m.What temperature would it correspond to if we had a monatomic gas having the same average kinetic energy (in $\degree$C)?

Accepted Answer

A)  273
B)  25
C)  36
D)  309
E)  51

Question 8

How much energy is in a 63 kHz photon of AM-radiation?

Accepted Answer

A)  1.0 *10-38 J
B)  6.6 *10-30 J
C)  4.2 *10-29 J
D)  3.1 * 10-30 J
E)  13 *10-29 J

Question 9

The experimental observation(s)below that require(s)a quantum explanation for the photoelectric effect

Accepted Answer

A)  is that more photoelectrons are emitted when the light frequency increases.
B)  is that the maximum kinetic energy of the photoelectrons is related linearly to the frequency of the light.
C)  is that every metal surface has a work function,a minimum amount of energy needed to free electrons.
D)  is that the stopping potential measures the kinetic energy of the photoelectrons.
E)  are all of the above.

Question 10

Assume electrons are accelerated through a potential difference of 25 000 V inside a TV picture tube.What is the minimum wavelength that could be produced when the electrons strike the phosphor? (1 Å = 10 - 10 m)

Accepted Answer

A)  0.50 Å
B)  1.0 Å
C)  10 Å
D)  100 Å
E)  0.25 Å

Question 11

A neutron has a mass of 1.67 *10 - 27 kg.The de Broglie wavelength is 1.4 *10 - 10 m.How fast is the neutron going? (in m/s)

Accepted Answer

A)  3.4 *103
B)  2.8 * 103
C)  3.9 * 103
D)  2.6 * 103
E)  1.7 * 103

Question 12

Film behind a double slit is exposed to light in the following way: First one slit is opened and light is allowed to go through that slit for time $\Delta$t.Then it is closed and the other slit is opened and light is allowed to go through that slit for the same time $\Delta$t.When the film is developed the pattern will be

Accepted Answer

A)  one single slit pattern.
B)  two superimposed single slit patterns,their centers displaced from each other by the distance between the two slits.
C)  one double slit pattern.
D)  two double slit patterns,their centers displaced from each other by the distance between the two slits.
E)  random darkening of the film.(no pattern at all)

Question 13

The "seeing ability" or resolution of radiation is determined by its wavelength.If an atom is approximately 10 ^- ¹⁰ m in diameter,how fast must an electron travel to have a wavelength smaller than the size of an atom?

Accepted Answer

The answer of The "seeing ability" or resolution of radiation...

Question 14

Frank says that quantum mechanics does not apply to baseballs because they do not jump from quantum state to quantum state when being thrown.Francine agrees with him.She says that there is no uncertainty in a baseball's position or momentum.Are they correct,or not,and why?

Accepted Answer

A)  They are correct because the first excited state of a baseball is at a higher energy that any baseball ever receives.Therefore we cannot determine whether or not there is uncertainty in its position or momentum.
B)  They are correct because the first excited state of a baseball is at a higher energy that any baseball ever receives.Therefore its position and momentum are completely uncertain until it is caught.
C)  They are wrong because the baseball goes through so many quantum states in being thrown that we cannot observe the transitions.The uncertainties in its position and momentum are too small to observe.
D)  They are wrong because the baseball goes through so many quantum states in being thrown that we cannot observe the transitions.Because of the number of transitions its position and momentum are completely uncertain until it is caught.
E)  Quantum mechanics states that they are correct as long as they do not make any observations,but wrong as soon as they begin to make observations.

Question 15

What is the maximum kinetic energy (in eV)of a photoelectron when a surface,whose work function is 5.0 eV,is illuminated by photons whose wavelength is 400 nm?

Accepted Answer

A)  3.1
B)  -1.9
C)  1.9
D)  0
E)  1.2

Question 16

A particle is in the second excited state of a one-dimensional box of length 1.0 m.What is its momentum (in kg . m/s)?

Accepted Answer

A)  6.6 *10 - 34
B)  3.3 *10 - 34
C)  9.9 * 10 - 34
D)  13 *10 - 34
E)  cannot be solved unless mass of particle is known

Question 17

A photon whose wavelength is = 5.0 * 10 - 11 m is scattered straight backward.What is the wavelength of the scattered wave?

Accepted Answer

A)  5.0 *10 - 11 m
B)  4.5 *10 - 11 m
C)  5.5 *10 - 11 m
D)  6.0 *10 - 11 m
E)  6.5 *10 - 11 m

Question 18

If the position of an electron (m = 9.11 *10 - 31 kg)could be measured to within 10 - 30 m,the uncertainty in the magnitude of its speed could be as much as

Accepted Answer

A)  6 *10 - 34 m/s.
B)  6 *1025 m/s.
C)  6 * 1030 m/s.
D)  1031 m/s.
E)  1061 m/s.

Question 19

The expectations value of a function f(x)of x when the wave function depends only on x is given by  =

Accepted Answer

A)    ∫−∞+∞f(x) ψ(x) dx\int _ { - \infty } ^ { + \infty } \sqrt { f ( x )  } \psi ( x )  d x∫−∞+∞​f(x) c34,79.3,68.167,158.7,102.5,238c34.3,79.3,51.8,119.3,52.5,120c340,-704.7,510.7,-1060.3,512,-1067l0 -0c4.7,-7.3,11,-11,19,-11H40000v40H1012.3s-271.3,567,-271.3,567c-38.7,80.7,-84,175,-136,283c-52,108,-89.167,185.3,-111.5,232c-22.3,46.7,-33.8,70.3,-34.5,71c-4.7,4.7,-12.3,7,-23,7s-12,-1,-12,-1s-109,-253,-109,-253c-72.7,-168,-109.3,-252,-110,-252c-10.7,8,-22,16.7,-34,26c-22,17.3,-33.3,26,-34,26s-26,-26,-26,-26s76,-59,76,-59s76,-60,76,-60zM1001 80h400000v40h-400000z"/>​ψ(x) dx  .
B)    ∫−∞+∞f(x) ψ(x) dx\int _ { - \infty } ^ { + \infty } f ( x )  \psi ( x )  d x∫−∞+∞​f(x) ψ(x) dx  .
C)    ∫−∞+∞f(x) ψ∗(x) dx\int _ { - \infty } ^ { + \infty } f ( x )  \psi ^ { * } ( x )  d x∫−∞+∞​f(x) ψ∗(x) dx  .
D)    ∫−∞+∞ψ∗(x) f(x) ψ(x) dx\int _ { - \infty } ^ { + \infty } \psi ^ { * } ( x )  f ( x )  \psi ( x )  d x∫−∞+∞​ψ∗(x) f(x) ψ(x) dx  .
E)    ∫−∞+∞ψ∗(x) f2(x) 2ψ(x) dx\int _ { - \infty } ^ { + \infty } \psi ^ { * } ( x )  \frac { f ^ { 2 } ( x )  } { 2 } \psi ( x )  d x∫−∞+∞​ψ∗(x) 2f2(x) ​ψ(x) dx  .

Question 20

When the potential energy of a system is independent of time,the wave function of the system

Accepted Answer

A)  is a constant.
B)  is directly proportional to the time.
C)  cannot be normalized.
D)  depends only on the center of mass,  R→\overrightarrow { \mathrm { R } }R-16.7 32-27.7 63.7-33 95 0 1.3-.2 2.7-.5 4-.3 1.3-.5 2.3-.5 3 0 7.3 6.7 11 20 11 8 0 13.2-.8 15.5-2.5 2.3-1.7 4.2-5.5 5.5-11.5 2-13.3 5.7-27 11-41 14.7-44.7 39-84.5 73-119.5s73.7-60.2 119-75.5c6-2 9-5.7 9-11s-3-9-9-11c-45.3-15.3-85-40.5-119-75.5s-58.3-74.8-73-119.5c-4.7-14-8.3-27.3-11-40-1.3-6.7-3.2-10.8-5.5-12.5-2.3-1.7-7.5-2.5-15.5-2.5-14 0-21 3.7-21 11 0 2 2 10.3 6 25 20.7 83.3 67 151.7 139 205zm0 0v40h399900v-40z"/>  ,of the system.
E)  depends on the vector positions,  r→\overrightarrow { \mathbf { r } }r-16.7 32-27.7 63.7-33 95 0 1.3-.2 2.7-.5 4-.3 1.3-.5 2.3-.5 3 0 7.3 6.7 11 20 11 8 0 13.2-.8 15.5-2.5 2.3-1.7 4.2-5.5 5.5-11.5 2-13.3 5.7-27 11-41 14.7-44.7 39-84.5 73-119.5s73.7-60.2 119-75.5c6-2 9-5.7 9-11s-3-9-9-11c-45.3-15.3-85-40.5-119-75.5s-58.3-74.8-73-119.5c-4.7-14-8.3-27.3-11-40-1.3-6.7-3.2-10.8-5.5-12.5-2.3-1.7-7.5-2.5-15.5-2.5-14 0-21 3.7-21 11 0 2 2 10.3 6 25 20.7 83.3 67 151.7 139 205zm0 0v40h399900v-40z"/>  i,of each particle in the system.

Exam 28: Quantum Physics

On a bright and sunny day,the intensity of solar radiation on the Earth's surface is 1 000 W/m².If the average wavelength of the sunlight is 500 nm,how many photons are incident on a square meter of the Earth's surface per second?

The threshold wavelength for photoelectric emission of a particular substance is 500 nm.What is the work function (in eV) ?

Your temperature is 98.6 $\degree$ F.Assuming your skin is a perfect radiator ( $\varepsilon$ = 1) ,determine the wavelength corresponding to the largest intensity (in $\mu$ m) .

A baseball (1 kg) has an energy of 100 joules.If its uncertainty in position is 1 m,what is the percentage uncertainty ( $\Delta$ p/p * 100) in the momentum of the baseball?

A particle is in the first excited state of a one-dimensional box of length 1.0 m.What is the minimum value of its momentum (in kg . m/s) ?

An electron is accelerated through a potential difference of 25 000 V.What is the de Broglie wavelength of the electron (in m) ?

A neutron has a mass of 1.67 10 ^- ²⁷ kg.Its de Broglie wavelength is 1.4 10 ^- ¹⁰ m.What temperature would it correspond to if we had a monatomic gas having the same average kinetic energy (in $\degree$ C) ?

How much energy is in a 63 kHz photon of AM-radiation?

The experimental observation(s) below that require(s) a quantum explanation for the photoelectric effect

Assume electrons are accelerated through a potential difference of 25 000 V inside a TV picture tube.What is the minimum wavelength that could be produced when the electrons strike the phosphor? (1 Å = 10 ^- ¹⁰ m)

A neutron has a mass of 1.67 10 ^- ²⁷ kg.The de Broglie wavelength is 1.4 10 ^- ¹⁰ m.How fast is the neutron going? (in m/s)

The "seeing ability" or resolution of radiation is determined by its wavelength.If an atom is approximately 10 ^- ¹⁰ m in diameter,how fast must an electron travel to have a wavelength smaller than the size of an atom?

Frank says that quantum mechanics does not apply to baseballs because they do not jump from quantum state to quantum state when being thrown.Francine agrees with him.She says that there is no uncertainty in a baseball's position or momentum.Are they correct,or not,and why?

What is the maximum kinetic energy (in eV) of a photoelectron when a surface,whose work function is 5.0 eV,is illuminated by photons whose wavelength is 400 nm?

A particle is in the second excited state of a one-dimensional box of length 1.0 m.What is its momentum (in kg . m/s) ?

A photon whose wavelength is = 5.0 * 10 ^- ¹¹ m is scattered straight backward.What is the wavelength of the scattered wave?

If the position of an electron (m = 9.11 *10 ^- ³¹ kg) could be measured to within 10 ^- ³⁰ m,the uncertainty in the magnitude of its speed could be as much as

The expectations value of a function f(x) of x when the wave function depends only on x is given by < f(x) > =

When the potential energy of a system is independent of time,the wave function of the system

Exam 28: Quantum Physics

On a bright and sunny day,the intensity of solar radiation on the Earth's surface is 1 000 W/m2.If the average wavelength of the sunlight is 500 nm,how many photons are incident on a square meter of the Earth's surface per second?

The threshold wavelength for photoelectric emission of a particular substance is 500 nm.What is the work function (in eV) ?

Your temperature is 98.6 °\degree° F.Assuming your skin is a perfect radiator ( ε\varepsilonε = 1) ,determine the wavelength corresponding to the largest intensity (in μ\muμ m) .

A baseball (1 kg) has an energy of 100 joules.If its uncertainty in position is 1 m,what is the percentage uncertainty ( Δ\DeltaΔ p/p * 100) in the momentum of the baseball?

A particle is in the first excited state of a one-dimensional box of length 1.0 m.What is the minimum value of its momentum (in kg . m/s) ?

An electron is accelerated through a potential difference of 25 000 V.What is the de Broglie wavelength of the electron (in m) ?

A neutron has a mass of 1.67 *10 - 27 kg.Its de Broglie wavelength is 1.4 *10 - 10 m.What temperature would it correspond to if we had a monatomic gas having the same average kinetic energy (in °\degree° C) ?

How much energy is in a 63 kHz photon of AM-radiation?

The experimental observation(s) below that require(s) a quantum explanation for the photoelectric effect

Assume electrons are accelerated through a potential difference of 25 000 V inside a TV picture tube.What is the minimum wavelength that could be produced when the electrons strike the phosphor? (1 Å = 10 - 10 m)

A neutron has a mass of 1.67 *10 - 27 kg.The de Broglie wavelength is 1.4 *10 - 10 m.How fast is the neutron going? (in m/s)

The "seeing ability" or resolution of radiation is determined by its wavelength.If an atom is approximately 10 - 10 m in diameter,how fast must an electron travel to have a wavelength smaller than the size of an atom?

Frank says that quantum mechanics does not apply to baseballs because they do not jump from quantum state to quantum state when being thrown.Francine agrees with him.She says that there is no uncertainty in a baseball's position or momentum.Are they correct,or not,and why?

What is the maximum kinetic energy (in eV) of a photoelectron when a surface,whose work function is 5.0 eV,is illuminated by photons whose wavelength is 400 nm?

A particle is in the second excited state of a one-dimensional box of length 1.0 m.What is its momentum (in kg . m/s) ?

A photon whose wavelength is = 5.0 * 10 - 11 m is scattered straight backward.What is the wavelength of the scattered wave?

If the position of an electron (m = 9.11 *10 - 31 kg) could be measured to within 10 - 30 m,the uncertainty in the magnitude of its speed could be as much as

The expectations value of a function f(x) of x when the wave function depends only on x is given by < f(x) > =

When the potential energy of a system is independent of time,the wave function of the system

On a bright and sunny day,the intensity of solar radiation on the Earth's surface is 1 000 W/m².If the average wavelength of the sunlight is 500 nm,how many photons are incident on a square meter of the Earth's surface per second?

Your temperature is 98.6 $\degree$ F.Assuming your skin is a perfect radiator ( $\varepsilon$ = 1) ,determine the wavelength corresponding to the largest intensity (in $\mu$ m) .

A baseball (1 kg) has an energy of 100 joules.If its uncertainty in position is 1 m,what is the percentage uncertainty ( $\Delta$ p/p * 100) in the momentum of the baseball?

A neutron has a mass of 1.67 10 ^- ²⁷ kg.Its de Broglie wavelength is 1.4 10 ^- ¹⁰ m.What temperature would it correspond to if we had a monatomic gas having the same average kinetic energy (in $\degree$ C) ?

Assume electrons are accelerated through a potential difference of 25 000 V inside a TV picture tube.What is the minimum wavelength that could be produced when the electrons strike the phosphor? (1 Å = 10 ^- ¹⁰ m)

A neutron has a mass of 1.67 10 ^- ²⁷ kg.The de Broglie wavelength is 1.4 10 ^- ¹⁰ m.How fast is the neutron going? (in m/s)

The "seeing ability" or resolution of radiation is determined by its wavelength.If an atom is approximately 10 ^- ¹⁰ m in diameter,how fast must an electron travel to have a wavelength smaller than the size of an atom?

A photon whose wavelength is = 5.0 * 10 ^- ¹¹ m is scattered straight backward.What is the wavelength of the scattered wave?

If the position of an electron (m = 9.11 *10 ^- ³¹ kg) could be measured to within 10 ^- ³⁰ m,the uncertainty in the magnitude of its speed could be as much as