Physics Boat 27

X-rays of wavelength of 0.065 0 nm undergo Compton scattering from free electrons in carbon. What is the wavelength of photons scattered at 90.0 relative to the incident beam? (h = 6.63 1034 Js, me = 9.11 1031 kg, c = 3.00 108 m/s, and 1 nm = 109 m) Question options: 1) 0.002 4 nm 2) 0.067 4 nm 3) 0.068 7 nm 4) 0.062 6 nm 5) 0.076 4 nm

2) 0.067 4 nm

Blue light ( = 460 nm) is incident on a piece of potassium ( = 2.20 eV). What is the maximum kinetic energy of the ejected photoelectrons? (h = 6.63 1034 Js, c = 3.00 108 m/s, 1 eV = 1.60 1019 J, and 1 nm = 109 m) Question options: 1) 1.0 eV 2) 0.50 eV 3) 0.25 eV 4) 4.9 eV 5) 6.2 eV

2) 0.50 eV

Light of wavelength 450 nm is incident on a target metal that has a work function of 1.80 eV. What stopping potential is required for this combination in a phototube? (h = 6.63 1034 Js, c = 3.00 108 m/s, 1 eV = 1.60 1019 J and 1 nm = 109 m) Question options: 1) 0.57 V 2) 0.96 V 3) 2.76 V 4) 4.56 V 5) 5.83 V

2) 0.96 V

According to de Broglie, as the momentum of a moving particle is tripled, the corresponding wavelength changes by what factor? Question options: 1) 1/9 2) 1/3 3) 3 4) 9 5) 1

2) 1/3

A sodium vapor lamp has a power output of 300 W. If 590 nm is the average wavelength of the source, about how many photons are emitted per second? (h = 6.63 1034 Js, c = 3.00 108 m/s, and 1 nm = 109 m) Question options: 1) 1017 2) 1021 3) 1025 4) 1029 5) 1031

2) 1021

A proton (mass = 1.67 1027 kg) has a kinetic energy of 1.00 MeV. If its momentum is measured with an uncertainty of 1.00%, what is the minimum uncertainty in its position? (h = 6.63 1034 Js, 1 eV = 1.6 1019 J) Question options: 1) 9.08 1013 m 2) 2.28 1013 m 3) 9.08 1014 m 4) 5.64 1014 m 5) 2.77 1014 m

2) 2.28 1013 m

What is the energy of a photon whose frequency is 6.0 1020 Hz? (h = 6.63 1034 Js and 1 eV = 1.60 1019 J) Question options: 1) 1.6 MeV 2) 2.5 MeV 3) 3.3 MeV 4) 4.8 MeV 5) 5.9 MeV

2) 2.5 MeV

Which process cannot occur if only one photon is involved? Question options: 1) Compton effect 2) pair production 3) the photoelectric effect 4) x-ray production 5) absorption of light by a single atom

1) Compton effect

A helium-neon laser emits red light having a wavelength of 632.8 nm and a power of 0.50 mW. How many photons are emitted each second? (h = 6.63 1034 Js, c = 3.00 108 m/s and 1 nm = 109 m) Question options: 1) 1.6 1015 2) 3.3 1016 3) 4.8 1017 4) 2.6 1018 5) 6.3 1018

1) 1.6 1015

According to Wien's displacement law, if the absolute temperature of a radiating blackbody is tripled, then the peak wavelength emitted will change by what factor? Question options: 1) 1/3 2) 1 3) 3 4) 9 5) 1/9

1) 1/3

Light of wavelength 480 nm is incident on a metallic surface with a resultant photoelectric stopping potential of 0.55 V. What is the work function of the metal? (h = 6.63 1034 Js, c = 3.00 108 m/s, 1 eV = 1.60 1019 J, and 1 nm = 109 m) Question options: 1) 2.04 eV 2) 3.19 eV 3) 2.59 eV 4) 0.55 eV 5) 0.27 eV

1) 2.04 eV

In an x-ray diffraction experiment, using x-rays of wavelength = 0.500 1010 m, a first-order maximum occurred at 5.00 off the crystal plane. Find the distance d between crystal planes. Question options: 1) 2.87 1010 m 2) 1.36 1010 m 3) 6.24 109 m 4) 1.93 109 m 5) 8.40 108 m

1) 2.87 1010 m

Light of wavelength 6.5 107 m has an energy of: (h = 6.63 1034 Js, c = 3.00 108 m/s) Question options: 1) 3.1 1019 J 2) 3.3 1019 J 3) 1.5 1019 J 4) 1.7 1019 J 5) 1.9 1019 J

1) 3.1 1019 J

A light beam is shining on a metal target that has a work function of 2.20 eV. If a stopping potential of 1.30 V is required, what is the wavelength of the incoming monochromatic light? (h = 6.63 1034 Js, c = 3.00 108 m/s, 1 eV = 1.60 1019 J and 1 nm = 109 m) Question options: 1) 355 nm 2) 497 nm 3) 744 nm 4) 1 421 nm 5) 1 812 nm

1) 355 nm

The "seeing" ability or resolution of radiation is determined by its wavelength. If the size of an atom is approximately 1010 m, how fast must an electron travel to have a wavelength smaller than that of an atom? (me = 9.11 1031 kg, h = 6.63 1034 Js) Question options: 1) 7.3 106 m/s 2) 3.4 106 m/s 3) 1.0 106 m/s 4) 5.4 105 m/s 5) 6.5 105 m/s

1) 7.3 106 m/s

Which of the following statements best describes the relation between the quantum theory and the photoelectric effect experiment? Question options: 1) Quantum theory explains the photoelectric effect. 2) The photoelectric effect contradicts quantum theory. 3) Quantum theory has no bearing on the photoelectric effect. 4) The photoelectric effect explains quantum theory. 5) The photoelectric effect is another name for quantum theory.

1) Quantum theory explains the photoelectric effect.

The ultraviolet catastrophe predicts that: Question options: 1) all objects should radiate extreme amounts of ultraviolet light. 2) as an object gets hotter its light will change from dull red to blue white. 3) a black body can absorb an infinite amount of radiation if the radiation is in the ultraviolet region. 4) the radiated energy approaches zero as the wavelength approaches zero. 5) a black body will be radiating energy in the ultraviolet region until its temperature approaches to the absolute zero.

1) all objects should radiate extreme amounts of ultraviolet light.

Which change will not change the kinetic energy of the most energetic electrons emitted in the photoelectric effect? Question options: 1) changing the brightness of the light 2) changing the frequency of the light 3) changing the metal the light is hitting 4) all of the above will change the electron's kinetic energy 5) all of the above will not change the electron's kinetic energy

1) changing the brightness of the light

In Bragg's law, 2d sin = m, how is measured? Question options: 1) from the reflecting crystal plane 2) from the normal to the reflecting crystal plane 3) from the direction of the incident beam 4) from the normal to the direction of the incident beam 5) None of the above

1) from the reflecting crystal plane

According to Einstein, what is true of the stopping potential for a photoelectric current as the wavelength of incident light becomes shorter? Question options: 1) increases 2) decreases 3) remains constant 4) stopping potential is directly proportional to wavelength 5) stopping potential is directly proportional to intensity

1) increases

In regard to the Compton scattering experiment with x-rays incident upon a carbon block, as the scattering angle becomes larger, what happens to the magnitude of difference between the incident and scattered wavelengths? Question options: 1) increases 2) decreases 3) remains constant 4) difference is maximum at a 45 angle of scatter 5) difference is maximum at a 60 angle of scatter

1) increases

Due to the dual nature of light and matter, either can act in an experiment as if it is a wave or a particle. In which experiment is the wave aspect exhibited for matter? Question options: 1) the Davisson and Germer experiment 2) the photoelectric effect 3) pair production 4) Compton scattering 5) Bragg diffraction

1) the Davisson and Germer experiment

According to Einstein, increasing the brightness of a beam of light without changing its color will increase: Question options: 1) the number of photons. 2) the energy of each photon. 3) the speed of the photons. 4) the frequency of the photons. 5) the mass of each photon.

1) the number of photons.

Sources of red, blue, and yellow light each emit light with a power of 50 mW. Which source emits more photons per second? Question options: 1) the red source 2) the blue source 3) the yellow source 4) They all emit the same number per second.

1) the red source

The spacing between atoms in KCl crystal is 3.1 1010 m. At what angle from the surface will a beam of 3.14 1011 m x-rays be constructively scattered? Question options: 1) 57 2) 2.9 3) 90 4) 10 5) 43

2) 2.9

The de Broglie wavelength of a 0.060 kg golf ball is 4.28 1034 m. What is its speed? (h = 6.63 1034 Js) Question options: 1) 15 m/s 2) 26 m/s 3) 31 m/s 4) 48 m/s 5) 84 m/s

2) 26 m/s

If the measured momentum of an electron is 3.20 1027 kgm/s with an uncertainty of 1.6 1029 kgm/s, what is the minimum uncertainty in the position? (h = 6.63 1034 Js) Question options: 1) 2.6 108 m 2) 3.3 106 m 3) 0.63 104 m 4) 1.1 103 m 5) 2.0 102 m

2) 3.3 106 m

What is the wavelength of a monochromatic light beam, where the photon energy is 5.00 1019 J? (h = 6.63 1034 Js, c = 3.00 108 m/s, and 1 nm = 109 m) Question options: 1) 354 nm 2) 398 nm 3) 414 nm 4) 787 nm 5) 875 nm

2) 398 nm

A quantum of radiation has an energy of 2.0 keV. What is its frequency? (h = 6.63 1034 Js and 1 eV = 1.60 1019 J) Question options: 1) 3.2 1017 Hz 2) 4.8 1017 Hz 3) 6.3 1017 Hz 4) 7.3 1017 Hz 5) 8.5 1017 Hz

2) 4.8 1017 Hz

In the Compton effect, what is the greatest change in wavelength that can occur? (h = 6.63 10-34 J·s, melectron = 9.11 10-31 kg, c = 3.00 108 m/s) Question options: 1) 2.43 10-12 m 2) 4.85 10-12 m 3) 9.70 10-12 m 4) equal to the incident wavelength 5) infinite

2) 4.85 10-12 m

What is the wavelength of a monochromatic light beam, where the photon energy is 3.00 eV? (h = 6.63 1034 Js, c = 3.00 108 m/s, 1 nm = 109 m, and 1 eV = 1.6 1019 J) Question options: 1) 311 nm 2) 414 nm 3) 622 nm 4) 1 243 nm 5) 1 735 nm

2) 414 nm

If barium has a work function of 2.60 eV, what is its cutoff wavelength when used as a phototube target? (h = 6.63 1034 Js, c = 3.00 108 m/s, 1 eV = 1.60 1019 J and 1 nm = 109 m) Question options: 1) 398 nm 2) 478 nm 3) 497 nm 4) 596 nm 5) 671 nm

2) 478 nm

What is the energy of a photon with the Compton wavelength (0.002 43 nm)? (h = 6.63 1034 Js, c = 3.00 108 m/s, and 1 eV = 1.60 1019 J) Question options: 1) 1.02 106 eV 2) 5.12 105 eV 3) 2.46 1013 eV 4) 8.19 1014 eV 5) 3.92 1014 eV

2) 5.12 105 eV

What is the maximum velocity of a photoelectron emitted from a surface with work function 5.00 eV when illuminated by 200 nm ultraviolet light? (melectron = 9.11 1031 kg, h = 6.63 1034 Js, 1 eV = 1.60 1019 J, and 1 nm = 109 m) Question options: 1) 800 000 m/s 2) 653 000 m/s 3) 431 000 m/s 4) 212 000 m/s 5) 184 000 m/s

2) 653 000 m/s

The uncertainty principle was derived by whom? Question options: 1) Schrödinger 2) Heisenberg 3) de Broglie 4) Compton 5) Einstein

2) Heisenberg

Star A has the peak of its blackbody radiation at A. Star B has its peak at B which is one fourth that of A. If Star A's surface temperature is TA, how does the surface temperature TB of Star B compare? Question options: 1) TB = 16 TA 2) TB = 4 TA 3) TB = TA/4 4) TB = TA/16 5) TB = TA

2) TB = 4 TA

That light has a dual nature is referring to light: Question options: 1) having high- or low-energy photons. 2) acting as waves and particles. 3) having energy and momentum. 4) undergoing pair production.

2) acting as waves and particles.

As the temperature of a radiation emitting blackbody becomes higher, what happens to the peak wavelength of the radiation? Question options: 1) increases 2) decreases 3) remains constant 4) is directly proportional to temperature 5) behaves differently for different temperatures

2) decreases

An important use of x-ray diffraction was: Question options: 1) the observation of Compton scattering. 2) determining the structure of the DNA molecule. 3) production of positrons. 4) observation of the photoelectric effect. 5) All of the above.

2) determining the structure of the DNA molecule.

X-ray production occurs in which process? Question options: 1) photons hitting a metal, emitting electrons 2) electrons hitting a metal, emitting photons 3) photons hitting a metal, emitting x-rays 4) electrons hitting a metal and scattering elastically 5) X-rays hitting electrons, emitting secondary x-rays

2) electrons hitting a metal, emitting photons

The Heisenberg uncertainty principle places restriction on the precision of simultaneously measuring both position and momentum. This principle can also be applied to the simultaneous measurement of two other variables, which are: Question options: 1) force and color. 2) energy and time interval. 3) mass and charge. 4) torque and frequency. 5) magnitude and direction of velocity.

2) energy and time interval.

Which of the following devices represent(s) a practical application of the photoelectric effect? Question options: 1) hologram 2) photocell 3) both of the above choices 4) none of the above choices

2) photocell

Rosalind Franklin was: Question options: 1) the maiden name of the wife of a president. 2) the producer of the x-ray diffraction photographs that led to the DNA structure. 3) the person who discovered that salt forms a crystal. 4) the discoverer of x-rays. 5) the discoverer of radioactivity.

2) the producer of the x-ray diffraction photographs that led to the DNA structure.

Blue light will not eject electrons from a certain metal; however, which one of the following may possibly eject electrons from that metal? Question options: 1) infrared 2) ultraviolet 3) red 4) green 5) yellow

2) ultraviolet

Who conceived the idea of using a crystal for observing diffraction of x-rays? Question options: 1) Roentgen 2) von Laue 3) W. L. Bragg 4) W. H. Bragg 5) Compton

2) von Laue

If a quantum of radiation has an energy of 2.0 keV, what is its wavelength? (h = 6.63 1034 Js, 1 eV = 1.60 1019 J, c = 3.00 108 m/s, and 1 nm = 109 m) Question options: 1) 0.32 nm 2) 0.41 nm 3) 0.62 nm 4) 1.02 nm 5) 1.24 nm

3) 0.62 nm

If a blackbody is at 2000 °C, what will be the peak wavelength emitted? Question options: 1) 1.67 m 2) 1.45 m 3) 1.27 m 4) 580 nm 5) 360 nm

3) 1.27 m

If a monochromatic light beam with quantum energy value of 3.0 eV incident upon a photocell where the work function of the target metal is 1.60 eV, what is the maximum kinetic energy of ejected electrons? Question options: 1) 4.6 eV 2) 4.8 eV 3) 1.4 eV 4) 2.4 eV 5) 3.8 eV

3) 1.4 eV

How much energy (in eV) does a photon of red light ( = 700 nm) have? (h = 6.63 1034 Js, c = 3.00 108 m/s, 1 eV = 1.60 1019 J, and 1 nm = 109 m) Question options: 1) 3.11 eV 2) 2.26 eV 3) 1.78 eV 4) 1.24 eV 5) 1.04 eV

3) 1.78 eV

Starting from rest, an electron accelerates through a potential difference of 40 V. What is its de Broglie wavelength? (h = 6.63 1034 Js, me = 9.11 1031 kg, and 1 eV = 1.60 1019 J) Question options: 1) 1.1 1010 m 2) 1.5 1010 m 3) 1.9 1010 m 4) 2.3 1010 m 5) 3.6 1010 m

3) 1.9 1010 m

If an x-ray machine were designed to operate at two separate accelerating voltages, one double the other, how would the shortest wavelength, min, hv, and the maximum frequency, fmax, hv, at the higher voltage compare to those (min, lv, fmax, lv) at the lower voltage? min, hv/ min, lv = ____, fmax, hv/ fmax, lv =____: Question options: 1) 2, 2. 2) 2, 1/2. 3) 1/2, 2 4) 1/2, 1/2. 5) 1, 1.

3) 1/2, 2

According to Heisenberg, as the uncertainty in the measurement of a particle's momentum is reduced by a factor of 2, by what factor is the uncertainty in that same particle's position changed? Question options: 1) 1/2 2) 1 3) 2 4) 4 5) 1/4

3) 2

Of the following energies for photons, which is the least energy that could result in photoelectron production if the work function is 3.00 eV? Question options: 1) 1.50 eV 2) 2.90 eV 3) 3.50 eV 4) 6.01 eV 5) 8.14 eV

3) 3.50 eV

An ultraviolet light beam having a wavelength of 130 nm is incident on a molybdenum surface with work function of 4.2 eV. What is the stopping potential? (h = 6.63 1034 Js, c = 3.00 108 m/s, 1 eV = 1.6 1019 J, and 1 nm = 109 m) Question options: 1) 1.3 V 2) 3.5 V 3) 5.4 V 4) 11.9 V 5) 13.6 V

3) 5.4 V

An electron microscope operates with electrons of kinetic energy 50.0 keV. What is the wavelength of these electrons? Assume this speed is not relativistic. (h = 6.63 1034 Js, c = 3.00 108 m/s, 1 eV = 1.60 1019 J, and me = 9.11 1031 kg) Question options: 1) 9.28 1010 m 2) 7.14 1011 m 3) 5.49 1012 m 4) 2.75 1013 m 5) 3.26 1013 m

3) 5.49 1012 m

What is the surface temperature of a distant star (which emits light as if it were a blackbody) where the peak wavelength is 480 nm? Hint: The surface of the human body at 35 oC has a peak wavelength of 941 m. (1 nm = 109 m = 10-3 m) Question options: 1) 4 510 K 2) 5 100 K 3) 6 040 K 4) 6 350 K 5) 7 200 K

3) 6 040 K

What is the frequency of monochromatic light where the photon energy is 5.5 1019 J? (h = 6.63 1034 Js) Question options: 1) 2.2 1014 Hz 2) 4.4 1014 Hz 3) 8.3 1014 Hz 4) 9.8 1014 Hz 5) 1.4 1015 Hz

3) 8.3 1014 Hz

Classical theories predict that most of the energy from a black body should be radiated: Question options: 1) as thermal radiation in the infrared region. 2) at the wavelength given by Wien's displacement law. 3) as ultraviolet light. 4) as gamma rays. 5) a black body should not radiate.

3) as ultraviolet light.

The Compton experiment demonstrated which of the following when an x-ray photon collides with an electron? Question options: 1) momentum is conserved 2) energy is conserved 3) momentum and energy are both conserved 4) wavelength of scattered photon equals that of incident photon 5) direction of a photon's motion after scattering is absolutely unpredictable

3) momentum and energy are both conserved

According to Einstein, as the wavelength of the incident monochromatic light beam becomes shorter, the work function of a target material in a phototube: Question options: 1) increases. 2) decreases. 3) remains constant. 4) is directly proportional to wavelength. 5) is inversely proportional to intensity.

3) remains constant.

Changing the accelerating voltage of an x-ray machine without changing the target material must change: Question options: 1) the work function of the material. 2) the wavelength of all the x-rays produced. 3) the wavelength of the minimum wavelength x-ray that will be produced. 4) Both b and c are correct. 5) None of the above choices is correct.

3) the wavelength of the minimum wavelength x-ray that will be produced.

What is the de Broglie wavelength for a proton (m = 1.67 1027 kg) moving at a speed of 6.0 106 m/s? (h = 6.63 1034 Js) Question options: 1) 2.0 1013 m 2) 0.33 1013 m 3) 1.3 1013 m 4) 0.66 1013 m 5) 0.23 1013 m

4) 0.66 1013 m

What is the highest frequency of the photons produced by a 90-kV x-ray machine? (h = 6.63 1034 Js) Question options: 1) 1.2 1019 Hz 2) 1.1 1019 Hz 3) 2.4 1019 Hz 4) 2.2 1019 Hz 5) 3.0 1019 Hz

4) 2.2 1019 Hz

What is the minimum x-ray wavelength produced when electrons are accelerated through a potential of 50 000 V? (h = 6.63 1034 Js, c = 3.00 108 m/s, and 1 eV = 1.60 1019 J) Question options: 1) 12.4 1012 m 2) 16.5 1012 m 3) 19.8 1012 m 4) 24.9 1012 m 5) 58.0 1012 m

4) 24.9 1012 m

Bragg reflection results in a first-order maximum at 14.2º. In this case, at what angle would the second-order maximum occur? Question options: 1) 7.1º 2) 14.2º 3) 28.4º 4) 29.4º 5) 42.6º

4) 29.4º

What is the energy of a photon that has the same wavelength as a 12-eV electron? (h = 6.63 1034 Js) Question options: 1) 5.6 10-16 eV 2) 12 eV 3) 24 eV 4) 3.5 keV 5) 560 keV

4) 3.5 keV

If the minimum x-ray wavelength produced is 13.5 1012 m, through what potential are the electrons accelerated in order to generate this radiation? (h = 6.63 1034 Js, c = 3.00 108 m/s, and 1 eV = 1.60 1019 J) Question options: 1) 33 300 V 2) 46 200 V 3) 75 000 V 4) 92 100 V 5) 122 100 V

4) 92 100 V

Who was the first to successfully explain the photoelectric effect? Question options: 1) Planck 2) Young 3) Bohr 4) Einstein 5) Heisenberg

4) Einstein

A photon absorbed by an electron will give up more energy to the electron if the photon: Question options: 1) is not spread out over many electrons. 2) is moving faster. 3) is moving slower. 4) has a higher frequency. 5) An electron cannot absorb a photon.

4) has a higher frequency.

The electron microscope's main advantage over the optical microscope is which of the following? Question options: 1) greater ease of portability 2) dispenses with need for a lens 3) higher power lens used 4) higher resolution possible 5) can be used for observing electrons

4) higher resolution possible

According to the de Broglie hypothesis, which of the following statements is applicable to the wavelength of a moving particle? Question options: 1) directly proportional to its energy 2) directly proportional to its momentum 3) inversely proportional to its energy 4) inversely proportional to its momentum 5) directly proportional to its mass

4) inversely proportional to its momentum

The wave function as derived in Schrödinger's equation is best described as being a measure of which of the following? Question options: 1) photon beam frequency 2) photon wavelength 3) particle wavelength 4) probability 5) particle wave number

4) probability

Of the following photons, which has the highest energy? Question options: 1) infrared 2) microwave 3) visible 4) ultraviolet 5) radio

4) ultraviolet