CUET UG Physics Booster Test 3-Dual Nature of Matter and De Broglie
📌 Answers are locked once submitted — results and explanations appear at the end.
QUESTION 1 OF 20
When visually observing an object, which mechanisms require which physical description?
1. Gathering and focussing light by the eye-lens utilizes the wave picture.
2. Absorption of light by the retina's rods and cones utilizes the photon picture.
3. The choice of description is fundamentally dependent on the nature of the interacting experiment.
4. All visual phenomena are purely described by continuous wave mechanics.
QUESTION 2 OF 20
Correct statements about radiation duality interactions in physical effects
1. The transfer of energy and momentum in discrete amounts demonstrates particle nature.
2. The photoelectric effect strictly involves energy transfer via photons.
3. The Compton effect strictly involves momentum transfer via photons.
4. The phenomenon of interference proves the localized absorption of photons.
QUESTION 3 OF 20
Symmetry arguments utilized by de Broglie
1. Nature inherently favors symmetry in its physical entities.
2. Matter and energy, the two basic physical entities, must have symmetrical character.
3. If electromagnetic radiation exhibits dual aspects, matter must also mirror this.
4. Matter waves are theorized to exist only for electrically charged sub-atomic particles.
QUESTION 4 OF 20
In formulating his revolutionary 1924 hypothesis, Louis de Broglie primarily relied on the conceptual argument that
QUESTION 5 OF 20
Match List I with List II regarding proportionality inside de Broglie's equation
| List I | List II |
|---|---|
| 1. λ versus p | a. Inversely proportional |
| 2. λ versus m (for constant v) | b. Inversely proportional |
| 3. λ versus v (for constant m) | c. Inversely proportional |
| 4. p versus v (for constant m) | d. Directly proportional |
QUESTION 6 OF 20
Incorrect statement about the functional role of h
QUESTION 7 OF 20
If an electron translates with speed v = 5.4 × 10⁶ m/s, what is its explicit momentum p?
(Using m = 9.11 × 10⁻³¹ kg)
QUESTION 8 OF 20
For the fundamental relation linking matter and wave properties, the specific attributes unified by h are respectively:
QUESTION 9 OF 20
The analytical relation for the momentum of a light quantum having wavelength λ is directly derived as:
QUESTION 10 OF 20
When correctly substituting p = hν/c into the de Broglie matter wave relation for a photon
QUESTION 11 OF 20
Regarding the calculated de Broglie values of a 0.12 kg ball moving at 20 m/s:
1. The calculated particle momentum is 2.40 kg m s⁻¹.
2. The associated matter wavelength is 2.76 × 10⁻³⁴ m.
3. The resulting wavelength is practically beyond any physical measurement.
4. The matter wave character dominates and is highly significant.
QUESTION 12 OF 20
Correct statements about unmeasurable matter waves in daily life
1. The relative heaviness (large m) of a macroscopic particle drastically decreases its de Broglie wavelength.
2. High-energy macroscopic objects exhibit clear quantum diffraction natively.
3. The extreme smallness of Planck's constant forces macroscopic λ to be tiny.
4. The de Broglie wavelengths of macroscopic objects are generally considered unmeasurable.
QUESTION 13 OF 20
Statements detailing the sub-atomic domain's wave mechanics
1. The wave character of sub-atomic particles is both significant and measurable.
2. Measurable wavelengths are typically of the order of atomic-plane spacing in crystals.
3. Sub-atomic particles possess unmeasurably small wavelengths due to high velocities.
4. Accelerated electron wavelengths are mathematically comparable to X-ray wavelengths.
QUESTION 14 OF 20
Using the calculated wavelengths from Example 11.3, what is the exact wavelength λ for the electron?
QUESTION 15 OF 20
Match List I with List II regarding foundational contributions in quantum mechanics
| List I | List II |
|---|---|
| 1. Proposed 1924 hypothesis of matter waves | a. Louis Victor de Broglie |
| 2. Developed full-fledged theory of wave mechanics | b. Erwin Schrodinger |
| 3. Awarded Nobel Prize in 1929 for electron wave nature | c. Louis Victor de Broglie |
| 4. Reasoned nature was fundamentally symmetrical | d. Louis Victor de Broglie |
QUESTION 16 OF 20
Incorrect statement about Louis de Broglie's Nobel Prize
QUESTION 17 OF 20
The expression for momentum p of a photon, which was confirmed scattered in the Compton effect, is formulated with h and c as:
QUESTION 18 OF 20
The structural order of atomic-planes spacing inside crystals
QUESTION 19 OF 20
When analyzing the dual attributes for a propagating matter wave, the physically meaningful velocity and the unmeaningful velocity are respectively:
QUESTION 20 OF 20
Detailed statements about electron energy distribution in metals
1. Free electrons are not entirely free to leave the constant potential of the metal.
2. The specific energy distribution differs fundamentally from Maxwell's theory.
3. Pauli's exclusion principle mathematically explains the energy distribution difference.
4. All free electrons require identical supplementary work function energy to escape.
Test Complete!
Answer Review
1 When visually observing an object, which mechanisms require which physical description?
1. Gathering and focussing light by the eye-lens utilizes the wave picture.
2. Absorption of light by the retina's rods and cones utilizes the photon picture.
3. The choice of description is fundamentally dependent on the nature of the interacting experiment.
4. All visual phenomena are purely described by continuous wave mechanics.
�� Vision involves both wave and particle aspects. �� Lens action is explained by wave optics. �� Retinal absorption involves photons.
- Statement 1 is correct because image formation and focusing by the eye lens are explained using the wave nature of light. → Statement 2 is correct because rods and cones absorb light through photon interactions. → Statement 3 is correct because the appropriate description depends on the phenomenon being studied. → Statement 4 is incorrect because photon interactions are essential in light absorption.
- �� Statement 4 → Continuous wave mechanics alone cannot explain absorption at the retinal receptors.
Used
- �� Elimination
Application:
- �� Remove the statement claiming wave theory alone explains all visual processes.
Final Logic:
- �� Statements 1, 2 and 3 correctly describe vision.
- Lens = Wave, Retina = Photon
2 Correct statements about radiation duality interactions in physical effects
1. The transfer of energy and momentum in discrete amounts demonstrates particle nature.
2. The photoelectric effect strictly involves energy transfer via photons.
3. The Compton effect strictly involves momentum transfer via photons.
4. The phenomenon of interference proves the localized absorption of photons.
�� Photoelectric effect supports photon energy transfer. �� Compton effect supports photon momentum transfer. �� Interference supports wave nature.
- Statement 1 is correct because discrete energy and momentum transfer are signatures of particle behavior. → Statement 2 is correct because photoelectric emission occurs through photon-electron interaction. → Statement 3 is correct because Compton scattering demonstrates momentum transfer by photons. → Statement 4 is incorrect because interference is evidence of wave behavior, not localized photon absorption.
- �� Statement 4 → Interference demonstrates wave superposition, not photon absorption.
Used
- �� Elimination
Application:
- �� Separate wave-based phenomena from particle-based phenomena.
Final Logic:
- �� Statements 1, 2 and 3 are correct.
- Photoelectric = Energy, Compton = Momentum
3 Symmetry arguments utilized by de Broglie
1. Nature inherently favors symmetry in its physical entities.
2. Matter and energy, the two basic physical entities, must have symmetrical character.
3. If electromagnetic radiation exhibits dual aspects, matter must also mirror this.
4. Matter waves are theorized to exist only for electrically charged sub-atomic particles.
�� de Broglie relied on symmetry arguments. �� Matter and energy are treated analogously. �� Matter waves are universal.
- Statements 1, 2 and 3 correctly describe de Broglie's reasoning. → Statement 4 is incorrect because matter waves are associated with all moving particles, not only charged subatomic particles.
- �� Statement 4 → Neutral particles also possess de Broglie wavelengths.
Used
- �� Elimination
Application:
- �� Remove the statement restricting matter waves to charged particles.
Final Logic:
- �� Statements 1, 2 and 3 are correct.
- Radiation Dual → Matter Dual
4 In formulating his revolutionary 1924 hypothesis, Louis de Broglie primarily relied on the conceptual argument that
�� de Broglie's argument was conceptual. �� Symmetry between matter and radiation was central. �� Matter waves were proposed theoretically.
- de Broglie argued that if radiation exhibits both wave and particle properties, matter should also possess dual characteristics. → This symmetry argument led to the matter-wave hypothesis. → Therefore option A is correct.
- �� Option B → Compton scattering concerned photons, not electron waves.
- �� Option C → Opposite of quantum reasoning.
- �� Option D → Incorrect historical and conceptual statement.
Used
- �� Contextual/Tonal Matching
Application:
- �� Recall the fundamental reasoning behind the hypothesis.
Final Logic:
- �� Symmetry motivated matter-wave theory.
- Symmetry → Matter Waves
5 Match List I with List II regarding proportionality inside de Broglie's equation
| List I | List II |
|---|---|
| 1. λ versus p | a. Inversely proportional |
| 2. λ versus m (for constant v) | b. Inversely proportional |
| 3. λ versus v (for constant m) | c. Inversely proportional |
| 4. p versus v (for constant m) | d. Directly proportional |
�� λ = h/p. �� p = mv. �� Wavelength decreases as mass or velocity increases.
Correct Match: List I — List II 1. λ versus p — a. Inversely proportional 2. λ versus m — b. Inversely proportional 3. λ versus v — c. Inversely proportional 4. p versus v — d. Directly proportional → Hence option B is correct.
- �� Options A, C and D contain incorrect proportionality relations.
Used
- �� Option Grouping
Application:
- �� Use λ = h/mv and p = mv.
Final Logic:
- �� λ varies inversely with p, m and v.
- Bigger p → Smaller λ
6 Incorrect statement about the functional role of h
�� h is extremely small. �� Large masses give tiny wavelengths. �� Macroscopic matter waves are unobservable.
- Since h is very small, macroscopic objects with large momentum have extremely small de Broglie wavelengths. → Therefore heavy objects do not possess easily observable wavelengths. → Hence option C is correct.
- �� Option A → Correct role in λ = h/p.
- �� Option B → Correct role in E = hν.
- �� Option D → Correctly describes the significance of h.
Used
- �� Elimination
Application:
- �� Identify the statement contradicting de Broglie wavelength behavior.
Final Logic:
- �� Heavy objects have tiny, not large, wavelengths.
- Small h → Tiny Macroscopic λ
7 If an electron translates with speed v = 5.4 × 10⁶ m/s, what is its explicit momentum p?
(Using m = 9.11 × 10⁻³¹ kg)
�� Use p = mv. �� Multiply mass and velocity. �� Express answer in scientific notation.
- p = mv = (9.11 × 10⁻³¹)(5.4 × 10⁶) = 4.92 × 10⁻²⁴ kg m/s → Therefore option A is correct.
- �� Option B → One power of ten too small.
- �� Option C → Two powers of ten too small.
- �� Option D → One power of ten too large.
Used
- �� Substitution
Application:
- �� Apply p = mv directly.
Final Logic:
- �� p = 4.92 × 10⁻²⁴ kg m/s.
- Momentum = mv
8 For the fundamental relation linking matter and wave properties, the specific attributes unified by h are respectively:
�� λ is a wave property. �� p is a particle property. �� h connects them.
- In the de Broglie equation: λ = h/p → λ represents wavelength (wave aspect). → p represents momentum (particle aspect). → Thus h unifies λ and p.
- �� Option A → Not the wave-particle pair connected by h.
- �� Option B → Not related by de Broglie's relation.
- �� Option C → Not involved.
Used
- �� Contextual/Tonal Matching
Application:
- �� Identify the quantities appearing in λ = h/p.
Final Logic:
- �� h links wavelength and momentum.
- λ ↔ p through h
9 The analytical relation for the momentum of a light quantum having wavelength λ is directly derived as:
�� Photon momentum depends on wavelength. �� Use de Broglie relation. �� Inverse dependence exists.
- From: λ = h/p Therefore: p = h/λ = h(λ)⁻¹ → Hence option A is correct.
- �� Option B → Represents λ/h.
- �� Option C → Incorrect square dependence.
- �� Option D → Incorrect dimensions.
Used
- �� Substitution
Application:
- �� Rearrange λ = h/p.
Final Logic:
- �� p = h/λ.
- Photon Momentum = h/λ
10 When correctly substituting p = hν/c into the de Broglie matter wave relation for a photon
�� Use λ = h/p. �� Substitute photon momentum. �� Result equals c/ν.
- Using: λ = h/p and p = hν/c → λ = h/(hν/c) = c/ν → This is exactly the electromagnetic wavelength of the photon. → Hence option B is correct.
- �� Option A → Effective mass is not obtained from this derivation.
- �� Option C → The derivation is perfectly consistent.
- �� Option D → No such conclusion follows.
Used
- �� Substitution
Application:
- �� Substitute photon momentum into de Broglie's equation.
Final Logic:
- �� de Broglie wavelength equals electromagnetic wavelength.
- Photon: λ = c/ν
11 Regarding the calculated de Broglie values of a 0.12 kg ball moving at 20 m/s:
1. The calculated particle momentum is 2.40 kg m s⁻¹.
2. The associated matter wavelength is 2.76 × 10⁻³⁴ m.
3. The resulting wavelength is practically beyond any physical measurement.
4. The matter wave character dominates and is highly significant.
�� Macroscopic objects have large momentum. �� Their de Broglie wavelengths are extremely small. �� Wave effects are practically unobservable.
- Momentum: p = mv = 0.12 × 20 = 2.40 kg m s⁻¹ → Wavelength: λ = h/p = (6.63 × 10⁻³⁴)/(2.40) = 2.76 × 10⁻³⁴ m → Such a tiny wavelength is far beyond present experimental detection. → Statement 4 is incorrect because wave effects are negligible for macroscopic objects.
- �� Statement 4 → Matter-wave effects do not dominate for macroscopic objects.
Used
- �� Substitution
Application:
- �� Calculate p and λ directly using standard formulas.
Final Logic:
- �� Statements 1, 2 and 3 are correct.
- Big Mass → Tiny λ
12 Correct statements about unmeasurable matter waves in daily life
1. The relative heaviness (large m) of a macroscopic particle drastically decreases its de Broglie wavelength.
2. High-energy macroscopic objects exhibit clear quantum diffraction natively.
3. The extreme smallness of Planck's constant forces macroscopic λ to be tiny.
4. The de Broglie wavelengths of macroscopic objects are generally considered unmeasurable.
�� λ = h/mv. �� Large mass reduces wavelength. �� Macroscopic diffraction is not observed.
- Statements 1, 3 and 4 correctly explain why macroscopic matter waves are unobservable. → Statement 2 is incorrect because quantum diffraction is not observable for ordinary macroscopic bodies.
- �� Statement 2 → Macroscopic objects do not show clear quantum diffraction.
Used
- �� Elimination
Application:
- �� Remove the statement inconsistent with observed macroscopic behavior.
Final Logic:
- �� Statements 1, 3 and 4 are correct.
- Large m → Small λ
13 Statements detailing the sub-atomic domain's wave mechanics
1. The wave character of sub-atomic particles is both significant and measurable.
2. Measurable wavelengths are typically of the order of atomic-plane spacing in crystals.
3. Sub-atomic particles possess unmeasurably small wavelengths due to high velocities.
4. Accelerated electron wavelengths are mathematically comparable to X-ray wavelengths.
�� Electron wavelengths are measurable. �� They are comparable to crystal spacing. �� They are similar to X-ray wavelengths.
- Statements 1, 2 and 4 are correct. → Electron wavelengths are typically around 10⁻¹⁰ m, comparable to crystal lattice spacing. → Statement 3 is incorrect because sub-atomic wavelengths are measurable and experimentally observed.
- �� Statement 3 → Contradicts electron diffraction experiments.
Used
- �� Elimination
Application:
- �� Identify the statement inconsistent with matter-wave observations.
Final Logic:
- �� Statements 1, 2 and 4 are correct.
- Electron λ ≈ X-ray λ
14 Using the calculated wavelengths from Example 11.3, what is the exact wavelength λ for the electron?
�� Use λ = h/p. �� Electron momentum is very small. �� Result lies in atomic dimensions.
- For the electron: p = 4.92 × 10⁻²⁴ kg m s⁻¹ → Therefore, λ = h/p = (6.63 × 10⁻³⁴)/(4.92 × 10⁻²⁴) ≈ 1.35 × 10⁻¹⁰ m = 0.135 × 10⁻⁹ m → Hence option A is correct.
- �� Option B → Ten times smaller.
- �� Option C → Hundred times smaller.
- �� Option D → Thousand times smaller.
Used
- �� Substitution
Application:
- �� Apply λ = h/p.
Final Logic:
- �� λ = 0.135 × 10⁻⁹ m.
- Electron λ ≈ 10⁻¹⁰ m
15 Match List I with List II regarding foundational contributions in quantum mechanics
| List I | List II |
|---|---|
| 1. Proposed 1924 hypothesis of matter waves | a. Louis Victor de Broglie |
| 2. Developed full-fledged theory of wave mechanics | b. Erwin Schrodinger |
| 3. Awarded Nobel Prize in 1929 for electron wave nature | c. Louis Victor de Broglie |
| 4. Reasoned nature was fundamentally symmetrical | d. Louis Victor de Broglie |
�� de Broglie proposed matter waves. �� Schrodinger developed wave mechanics. �� Nobel Prize recognized de Broglie's contribution.
Correct Match: List I — List II 1. Proposed 1924 hypothesis of matter waves — a. Louis Victor de Broglie 2. Developed full-fledged theory of wave mechanics — b. Erwin Schrodinger 3. Awarded Nobel Prize in 1929 for electron wave nature — c. Louis Victor de Broglie 4. Reasoned nature was fundamentally symmetrical — d. Louis Victor de Broglie → Hence option A is correct.
- �� Options B, C and D contain incorrect scientist-contribution pairings.
Used
- �� Option Grouping
Application:
- �� Associate scientists with their known contributions.
Final Logic:
- �� Only Option A gives all correct matches.
- de Broglie → Matter Waves, Schrodinger → Wave Mechanics
16 Incorrect statement about Louis de Broglie's Nobel Prize
�� Photoelectric equation is associated with Einstein. �� de Broglie proposed matter waves. �� Nobel Prize was awarded in 1929.
- de Broglie received the Nobel Prize for proposing the wave nature of matter. → The photoelectric equation was formulated by Einstein. → Therefore option C is correct.
- �� Option A → Correct.
- �� Option B → Correct.
- �� Option D → Correct.
Used
- �� Elimination
Application:
- �� Distinguish Einstein's work from de Broglie's contribution.
Final Logic:
- �� Photoelectric equation was not de Broglie's achievement.
- Einstein → Photoelectric, de Broglie → Matter Waves
17 The expression for momentum p of a photon, which was confirmed scattered in the Compton effect, is formulated with h and c as:
�� Photon momentum depends on frequency. �� Derived from E = pc. �� Important in Compton scattering.
- Photon energy: E = hν → Also: E = pc → Therefore: p = hν/c = hν(c)⁻¹ → Hence option C is correct.
- �� Option A → Incorrect dimensions.
- �� Option B → Incorrect arrangement.
- �� Option D → Incorrect dependence on c.
Used
- �� Substitution
Application:
- �� Use E = hν and E = pc.
Final Logic:
- �� p = hν/c.
- Photon Momentum = hν/c
18 The structural order of atomic-planes spacing inside crystals
�� Crystal spacing is about 10⁻¹⁰ m. �� Electron wavelengths are similar. �� Diffraction becomes possible.
- Atomic plane spacing and electron wavelengths are of comparable magnitude. → This allows diffraction experiments and measurement of matter waves. → Therefore option A is correct.
- �� Option B → Electron wavelengths can be measured.
- �� Option C → X-rays interact strongly with crystal planes.
- �� Option D → No such proportionality exists.
Used
- �� Contextual/Tonal Matching
Application:
- �� Relate crystal spacing to diffraction conditions.
Final Logic:
- �� Comparable scales enable measurement.
- Crystal Scale ≈ Electron Scale
19 When analyzing the dual attributes for a propagating matter wave, the physically meaningful velocity and the unmeaningful velocity are respectively:
�� Group velocity equals particle velocity. �� Phase velocity lacks direct physical significance. �� Matter waves travel as wave packets.
- Group velocity represents the actual velocity of the particle. → Phase velocity does not represent physical transport of matter. → Hence option A is correct.
- �� Option B → Reversed order.
- �� Option C → Not the standard interpretation.
- �� Option D → Incorrect classification.
Used
- �� Contextual/Tonal Matching
Application:
- �� Recall definitions of group and phase velocity.
Final Logic:
- �� Group velocity is meaningful; phase velocity is not.
- Group = Real, Phase = Formal
20 Detailed statements about electron energy distribution in metals
1. Free electrons are not entirely free to leave the constant potential of the metal.
2. The specific energy distribution differs fundamentally from Maxwell's theory.
3. Pauli's exclusion principle mathematically explains the energy distribution difference.
4. All free electrons require identical supplementary work function energy to escape.
�� Electrons are bound within the metal. �� They obey quantum statistics. �� Pauli exclusion principle is important.
- Statement 1 is correct because electrons remain confined by the metal's potential barrier. → Statement 2 is correct because electrons follow Fermi-Dirac statistics rather than Maxwell-Boltzmann statistics. → Statement 3 is correct because the exclusion principle governs electron occupancy of energy states. → Statement 4 is incorrect because electrons possess different initial energies inside the metal.
- �� Statement 4 → Different electrons require different additional energies depending on their initial energy states.
Used
- �� Elimination
Application:
- �� Remove the statement assuming identical electron energies.
Final Logic:
- �� Statements 1, 2 and 3 are correct.
- Metal Electrons → Fermi + Pauli
