Multiple Choice
21.1 Planck and Quantum Nature of Light
A perfect blackbody is a perfect absorber of energy transferred by what method?
- conduction
- convection
- induction
- radiation
Which of the following is a physical entity that is quantized?
- electric charge of an ion
- frequency of a sound
- speed of a car
Find the energy in joules of photons of radio waves that leave an FM station that has a 90.0-MHz broadcast frequency.
- 1.8 × 10−25 J
- 1.11 × 10−25 J
- 7.1 × 10−43 J
- 5.96 × 10-26 J
Which region of the electromagnetic spectrum will provide photons of the least energy?
- infrared light
- radio waves
- ultraviolet light
- X-rays
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Not all heat is in the form of light energy.
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Not all light energy falls in the visible portion of the electromagnetic spectrum.
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All heat is in the form of light energy.
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All light energy falls in the visible portion of the electromagnetic spectrum.
Given two stars of equivalent size, which will have a greater temperature: a red dwarf or a yellow dwarf? Explain. Note—Our sun is considered a yellow dwarf.
- a yellow dwarf, because yellow light has lower frequency
- a red dwarf, because red light has lower frequency
- a red dwarf, because red light has higher frequency
- a yellow dwarf, because yellow light has higher frequency
21.2 Einstein and the Photoelectric Effect
What is a quantum of light called?
- electron
- neutron
- photon
- proton
-
Immediate ejection of electrons upon exposure of a material to light.
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Exposure to light causes an electrical response in many materials.
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The speed of ejected electrons is independent of light intensity.
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Electrical activity from a given material requires a specific frequency of light.
-
2.3\,\text{eV}
-
7.3\,\text{eV}
-
11.5\,\text{eV}
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\text{2.7}\,\text{eV}
Which of the following terms translates to light-producing voltage?
- photoelectric
- quantum mechanics
- photoconductive
- photovoltaic
-
Long wavelength EM radiation photons carry less energy and therefore have greater ability to disrupt materials through the photoelectric effect.
-
Long wavelength EM radiation photons carry more energy and therefore have greater ability to disrupt materials through the photoelectric effect.
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High frequency EM radiation photons carry less energy and therefore have lower ability to disrupt materials through the photoelectric effect.
-
High frequency EM radiation photons carry more energy and therefore have greater ability to disrupt materials through the photoelectric effect.
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UV, X-rays, and gamma rays are capable of ejecting photons from a surface.
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UV, X-rays, and gamma rays are capable of ejecting neutrons from a surface.
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UV, X-rays, and gamma rays are capable of ejecting protons from a surface.
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UV, X-rays, and gamma rays are capable of ejecting electrons from a surface.
21.3 The Dual Nature of Light
What two particles interact in Compton scattering?
- photon and electron
- proton and electron
- neutron and electron
- proton and neutron
What is the momentum of a 500-nm photon?
- 8.35 × 10−26 kg ⋅ m/s
- 3.31 × 10−40 kg ⋅ m/s
- 7.55 × 1026 kg ⋅ m/s
- 1.33 × 10-27 kg ⋅ m/s
The conservation of what fundamental physics principle is behind the technology of solar sails?
- charge
- mass
- momentum
- angular momentum
Terms like frequency, amplitude, and period are tied to what component of wave-particle duality?
- neither the particle nor the wave model of light
- both the particle and wave models of light
- the particle model of light
- the wave model of light
Why was it beneficial for Compton to scatter electrons using X-rays and not another region of light like microwaves?
- because X-rays are more penetrating than microwaves
- because X-rays have lower frequency than microwaves
- because microwaves have shorter wavelengths than X-rays
- because X-rays have shorter wavelength than microwaves