Lượng tử ánh sáng Practice Questions
THPT (Vietnam) · THPT Vật lý · 147 free MCQs with instant results and detailed explanations.
147
Total
44
Easy
80
Medium
23
Hard
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Sample Questions from Lượng tử ánh sáng
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Q1
Easy
What is the fundamental particle of light called?
A.
Photon
B.
Electron
C.
Neutron
D.
Proton
Show Answer & Explanation
Correct Answer: A
A photon is the basic unit of light and all other forms of electromagnetic radiation. Unlike electrons, neutrons, and protons, photons have no mass and carry energy and momentum.
Q2
Easy
Which equation represents the relationship between energy and frequency of a photon?
A.
E = mc^2
B.
E = hf
C.
E = mv^2
D.
E = kx
Show Answer & Explanation
Correct Answer: B
The equation E = hf shows that the energy (E) of a photon is directly proportional to its frequency (f), where h is Planck's constant. This is a fundamental concept in quantum physics.
Q3
Easy
If the frequency of a photon is doubled, what happens to its energy?
A.
It remains the same
B.
It doubles
C.
It is halved
D.
It quadruples
Show Answer & Explanation
Correct Answer: B
According to the equation E = hf, if the frequency (f) is doubled, the energy (E) will also double since they are directly proportional. This shows the linear relationship between energy and frequency.
Q4
Medium
What is the energy of a photon with a frequency of 5 x 10^14 Hz?
A.
3.31 x 10^-19 J
B.
6.63 x 10^-19 J
C.
2.49 x 10^-19 J
D.
1.24 x 10^-19 J
Show Answer & Explanation
Correct Answer: B
The energy of a photon can be calculated using the formula E = h * f, where h (Planck's constant) = 6.63 x 10^-34 J*s. So, E = 6.63 x 10^-34 * 5 x 10^14 = 6.63 x 10^-19 J.
Q5
Medium
Which of the following statements best describes the photoelectric effect?
A.
Light is a wave and cannot eject electrons.
B.
Electrons are ejected from a metal surface when exposed to light of sufficient frequency.
C.
Photoelectric effect occurs only in metals with low work function.
D.
Increasing light intensity increases the energy of ejected electrons.
Show Answer & Explanation
Correct Answer: B
The photoelectric effect states that electrons can be ejected from a metal surface when it absorbs photons of light with a frequency above a certain threshold frequency.
Q6
Medium
If the wavelength of a photon is doubled, how does its frequency change?
A.
It doubles.
B.
It is halved.
C.
It remains the same.
D.
It quadruples.
Show Answer & Explanation
Correct Answer: B
The relationship between wavelength (λ) and frequency (f) is given by the equation c = λ * f. If λ is doubled, f must be halved to maintain the speed of light constant (c).
Q7
Medium
A laser emits light at a wavelength of 600 nm. What is the energy of a single photon from this laser?
A.
3.31 x 10^-19 J
B.
2.07 x 10^-19 J
C.
1.24 x 10^-19 J
D.
4.14 x 10^-19 J
Show Answer & Explanation
Correct Answer: A
The energy of a photon can be calculated using E = hc/λ, where h = 6.63 x 10^-34 J*s and c = 3 x 10^8 m/s. Substituting λ = 600 nm (or 600 x 10^-9 m) gives E = (6.63 x 10^-34 * 3 x 10^8) / (600 x 10^-9) = 3.31 x 10^-19 J.
Q8
Hard
A photon of light collides with an electron at rest and transfers half of its energy to the electron. If the initial energy of the photon is E, what will be the total energy of the electron after the collision?
A.
E/2
B.
E + E/2
C.
E/4
D.
E
Show Answer & Explanation
Correct Answer: B
The total energy of the electron after the collision is the energy it gained from the photon plus its rest energy. Since the photon transfers half of its energy (E/2) to the electron, the total energy becomes the rest mass energy of the electron plus the energy received from the photon, leading to E (rest mass) + E/2 = E + E/2.
Q9
Hard
In a double-slit experiment, light of wavelength 500 nm produces a certain interference pattern on a screen. If the distance between the slits is 0.2 mm and the screen is 2 m away from the slits, what is the distance between the first and second bright fringes on the screen?
A.
0.5 cm
B.
1.0 cm
C.
2.0 cm
D.
4.0 cm
Show Answer & Explanation
Correct Answer: B
The distance between the bright fringes can be calculated using the formula y = (m * λ * L) / d, where y is the fringe separation, m is the fringe order, λ is the wavelength, L is the distance to the screen, and d is the slit separation. For the first and second fringes (m=1 and m=2), the distance is (1 * 500 nm * 200 cm) / 0.2 cm, which gives 1.0 cm for the distance between the first and second bright fringes.
Q10
Hard
A photon of light has a wavelength of 500 nm. What is its energy in electron volts (eV)?
A.
2.48 eV
B.
1.24 eV
C.
3.15 eV
D.
5.00 eV
Show Answer & Explanation
Correct Answer: A
The energy of a photon can be calculated using the formula E = hc/λ. Here, h (Planck's constant) is 6.626 x 10^-34 J·s, c (speed of light) is 3.00 x 10^8 m/s, and λ is 500 nm (or 500 x 10^-9 m). Calculating gives E ≈ 2.48 eV, making option A the correct answer.
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Lượng tử ánh sáng — THPT (Vietnam) THPT Vật lý Practice Questions Online
This page contains 147 practice MCQs for the chapter Lượng tử ánh sáng in THPT (Vietnam) THPT Vật lý. The questions are organized by difficulty — 44 easy, 80 medium, 23 hard — so you can choose the right level for your preparation.
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