Question 1

What primary wavelength and corresponding photon energy is emitted by a body at:
(a) 400.°C?
(b) 800.°C?
(c) 1200.°C?

Accepted Answer

(a)4.31 μm,0.288 eV

Question 2

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

Accepted Answer

A)  It is halved. 
B)  It stays the same. 
C)  It is doubled. 
D)  It is quadrupled. 
E)  It is reduced by one-fourth. 
A)  It is halved. 
B)  It stays the same. 
C)  It is doubled. 
D)  It is quadrupled. 
E)  It is reduced by one-fourth.

Question 3

In quantum tunneling, electrons and other quantum particles can tunnel through a region of space that would be forbidden to them if they were classical particles.

Accepted Answer

A) True 
 B)False

Question 4

A small gas laser of the type used in classrooms may radiate light at a power level of 2.0 mW. If the wavelength of the emitted light is 642. nm, how many photons are emitted per second?

Accepted Answer

The answer of A small gas laser of the type...

Question 5

What are the shortest wavelength X-rays produced by a 50,000-V X-ray tube?

Accepted Answer

The answer of What are the shortest wavelength X-rays produced...

Question 6

Which one of the following is the correct expression for the energy of the photon?

Accepted Answer

A)  E = h/f 
B)  E = hλ/c 
C)  E = hc/λ 
D)  E = λc/h 
E)  E = hλ 
A)  E = h/f 
B)  E = hλ/c 
C)  E = hc/λ 
D)  E = λc/h 
E)  E = hλ

Question 7

The cosmic background radiation permeating the universe has the spectrum of a 2.7 K thermal radiator. What is the peak wavelength?

Accepted Answer

1.1 mm (mi

Question 8

The wavelength of a photon decreases when it is scattered from an electron.

Accepted Answer

A) True 
 B)False

Question 9

What is the energy of a photon with a frequency of 6.60 × 1015 Hz?

Accepted Answer

A)  27.3 eV 
B)  12.3 eV 
C)  18.1 eV 
D)  19.6 eV 
E)  6.60 eV 
A)  27.3 eV 
B)  12.3 eV 
C)  18.1 eV 
D)  19.6 eV 
E)  6.60 eV

Question 10

Light with a wavelength of 310 nm is incident on a metal that has a work function of 3.8 eV. What is the maximum kinetic energy that a photoelectron ejected in this process can have?

Accepted Answer

A)  0.62 × 10-19 J 
B)  0.21 × 10-19 J 
C)  0.36 × 10-19 J 
D)  0.48 × 10-19 J 
E)  0.33 × 10-19 J 
A)  0.62 × 10-19 J 
B)  0.21 × 10-19 J 
C)  0.36 × 10-19 J 
D)  0.48 × 10-19 J 
E)  0.33 × 10-19 J

Question 11

Which one of the following is the correct expression of the cutoff frequency of the metal in terms of its work function?

Accepted Answer

A)  fo = Wo/h 
B)  fo = Wo/c 
C)  fo = c/Wo 
D)  fo = h/Wo 
E)  None of the other choices is correct. 
A)  fo = Wo/h 
B)  fo = Wo/c 
C)  fo = c/Wo 
D)  fo = h/Wo 
E)  None of the other choices is correct.

Question 12

What is the longest wavelength of light that can cause photoelectron emission from a metal that has a work function of 2.20 eV?

Accepted Answer

A)  417 nm 
B)  257 nm 
C)  344 nm 
D)  564 nm 
E)  610 nm 
A)  417 nm 
B)  257 nm 
C)  344 nm 
D)  564 nm 
E)  610 nm

Question 13

If the momentum of an electron is 1.95 × 10-27 kg∙m/s, what is its de Broglie wavelength?

Accepted Answer

A)  340 nm 
B)  210 nm 
C)  170 nm 
D)  420 nm 
E)  520 nm 
A)  340 nm 
B)  210 nm 
C)  170 nm 
D)  420 nm 
E)  520 nm

Question 14

An electron is trapped in a box of width 0.10 nm. What is the wavelength of the photon emitted when an electron makes a transition from the n = 3 to the n = 1 state?

Accepted Answer

The answer of An electron is trapped in a box...

Question 15

A beam of X-rays at a certain wavelength are scattered from a free electron at rest and the scattered beam is observed at 45.0° to the incident beam. What is the Compton shift?

Accepted Answer

A)  1.75 × 10-13 m 
B)  2.76 × 10-13 m 
C)  0 m 
D)  3.56 × 10-13 m 
E)  7.11 × 10-13 m 
A)  1.75 × 10-13 m 
B)  2.76 × 10-13 m 
C)  0 m 
D)  3.56 × 10-13 m 
E)  7.11 × 10-13 m

Question 16

When you decrease, by a factor of two, the wavelength of the light causing photoelectrons to be emitted from a metal surface, the kinetic energy of the photoelectrons will

Accepted Answer

A)  decrease by a factor of 2. 
B)  double 
C)  more than double. 
D)  increase by a factor of   . 
E)  decrease by a factor of   . 
A)  decrease by a factor of 2. 
B)  double 
C)  more than double. 
D)  increase by a factor of   . 
E)  decrease by a factor of   .

Question 17

A 2.00 kg mass is attached to a spring with a spring constant of 48.0 N/m. If the maximum speed of the mass in this system is 1.14 m/s, what is the energy of the quanta of energy in this system?

Accepted Answer

A)  2.23 × 10-34 J 
B)  6.63 J 
C)  6.63 × 10-34 J 
D)  5.17 J 
E)  5.17 × 10-34 J 
A)  2.23 × 10-34 J 
B)  6.63 J 
C)  6.63 × 10-34 J 
D)  5.17 J 
E)  5.17 × 10-34 J

Question 18

The rest mass of a photon is zero kg.

Accepted Answer

A) True 
 B)False

Question 19

What is the cutoff frequency for a metal surface that has a work function of 5.42 eV?

Accepted Answer

A)  1.31 × 1015 Hz 
B)  2.01 × 1015 Hz 
C)  3.01 × 1015 Hz 
D)  5.02 × 1015 Hz 
E)  6.04 × 1015 Hz 
A)  1.31 × 1015 Hz 
B)  2.01 × 1015 Hz 
C)  3.01 × 1015 Hz 
D)  5.02 × 1015 Hz 
E)  6.04 × 1015 Hz

Question 20

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?

Accepted Answer

A)  231 nm 
B)  14.0 nm 
C)  62.4 nm 
D)  344 nm 
E)  653 nm 
A)  231 nm 
B)  14.0 nm 
C)  62.4 nm 
D)  344 nm 
E)  653 nm

Exam 30: Quantum Physics

What primary wavelength and corresponding photon energy is emitted by a body at: (a) 400.°C? (b) 800.°C? (c) 1200.°C?

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

In quantum tunneling, electrons and other quantum particles can tunnel through a region of space that would be forbidden to them if they were classical particles.

A small gas laser of the type used in classrooms may radiate light at a power level of 2.0 mW. If the wavelength of the emitted light is 642. nm, how many photons are emitted per second?

What are the shortest wavelength X-rays produced by a 50,000-V X-ray tube?

Which one of the following is the correct expression for the energy of the photon?

The cosmic background radiation permeating the universe has the spectrum of a 2.7 K thermal radiator. What is the peak wavelength?

The wavelength of a photon decreases when it is scattered from an electron.

What is the energy of a photon with a frequency of 6.60 × 1015 Hz?

Light with a wavelength of 310 nm is incident on a metal that has a work function of 3.8 eV. What is the maximum kinetic energy that a photoelectron ejected in this process can have?

Which one of the following is the correct expression of the cutoff frequency of the metal in terms of its work function?

What is the longest wavelength of light that can cause photoelectron emission from a metal that has a work function of 2.20 eV?

If the momentum of an electron is 1.95 × 10-27 kg∙m/s, what is its de Broglie wavelength?

An electron is trapped in a box of width 0.10 nm. What is the wavelength of the photon emitted when an electron makes a transition from the n = 3 to the n = 1 state?

A beam of X-rays at a certain wavelength are scattered from a free electron at rest and the scattered beam is observed at 45.0° to the incident beam. What is the Compton shift?

When you decrease, by a factor of two, the wavelength of the light causing photoelectrons to be emitted from a metal surface, the kinetic energy of the photoelectrons will

A 2.00 kg mass is attached to a spring with a spring constant of 48.0 N/m. If the maximum speed of the mass in this system is 1.14 m/s, what is the energy of the quanta of energy in this system?

The rest mass of a photon is zero kg.

What is the cutoff frequency for a metal surface that has a work function of 5.42 eV?

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?

Introduction to Physics

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What is the energy of a photon with a frequency of 6.60 × 10¹⁵ Hz?

If the momentum of an electron is 1.95 × 10^-27 kg∙m/s, what is its de Broglie wavelength?