JEE (Advanced) · Physics, Class 12
Dual Nature of Matter and Radiation: JEE Advanced PYQ, 2007–2026
Dual Nature of Matter and Radiation (Physics, Class 12) has been asked 20 times in the 40 JEE (Advanced) papers from 2007–2026: about 0.5 questions a paper, 3% of all Physics questions. It is the 16th most-asked of 19 Physics chapters. The two 2026 papers had 0 from it. Last checked 28 October 2026.
Questions per year, both papers
Year by year.
| Year | Questions |
|---|---|
| 2007 | 1in 2 papers |
| 2008 | 0in 2 papers |
| 2009 | 4in 2 papers |
| 2010 | 1in 2 papers |
| 2011 | 1in 2 papers |
| 2012 | 1in 2 papers |
| 2013 | 1in 2 papers |
| 2014 | 1in 2 papers |
| 2015 | 1in 2 papers |
| 2016 | 2in 2 papers |
| 2017 | 1in 2 papers |
| 2018 | 1in 2 papers |
| 2019 | 0in 2 papers |
| 2020 | 1in 2 papers |
| 2021 | 1in 2 papers |
| 2022 | 1in 2 papers |
| 2023 | 1in 2 papers |
| 2024 | 0in 2 papers |
| 2025 | 1in 2 papers |
| 2026 | 0in 2 papers |
Each year has two papers, and the number of questions has fallen over time, so compare per paper and expect some drift.
Inside the chapter
Topics asked most.
- Photoelectric effect11
- de Broglie wavelength9
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5 Dual Nature of Matter and Radiation questions to practise.
Our own questions, written in the JEE Advanced pattern and checked, each with an explanation. Pick an option to see the answer.
Q1 · Physics · Dual Nature of Matter and Radiation
Light of wavelength 124 nm falls on a metal of work function 4.0 eV. What is the de Broglie wavelength of the fastest photoelectrons emitted? (hc = 1240 eV nm; for an electron h²/2m = 1.5 eV nm²)
Answer: (D)
The photon energy is 1240/124 = 10 eV, so the fastest electrons have K = 10 − 4.0 = 6.0 eV. From λ = h/√(2mK), λ² = (h²/2m)/K = 1.5/6.0 = 0.25 nm², and λ = 0.50 nm.
Q2 · Physics · Dual Nature of Matter and Radiation
Hydrogen gas (molar mass 2 g mol⁻¹) and oxygen gas (molar mass 32 g mol⁻¹) are both at the same temperature. The de Broglie wavelength of each molecule is calculated from its mean translational kinetic energy, (3/2)k_BT. What is the ratio λ(H₂) : λ(O₂)?
Answer: (A)
The de Broglie wavelength is λ = h/p, and p = √(2mK). At the same temperature the mean translational kinetic energy K = (3/2)k_BT is the same for both gases. So λ = h/√(2mK) is proportional to 1/√m. Then λ(H₂)/λ(O₂) = √(m(O₂)/m(H₂)) = √(32/2) = √16 = 4. The lighter hydrogen molecule has the longer wavelength.
Q3 · Physics · Dual Nature of Matter and Radiation
An electron and an alpha particle (a helium nucleus, charge +2e) are each accelerated from rest, the electron through a potential difference V_e and the alpha particle through V_α. Both end up with the same de Broglie wavelength. Treat both as non-relativistic and take m_α = 7344 m_e. What is the ratio V_e / V_α?
Answer: (A)
The de Broglie wavelength is λ = h/p. For equal wavelengths the momenta must be equal. A particle of charge q accelerated through V from rest has kinetic energy qV, so p = √(2mqV). Setting the momenta equal gives m_e·e·V_e = m_α·(2e)·V_α. Hence V_e/V_α = 2m_α/m_e = 2 × 7344 = 14688. The electron needs a much larger potential because it is far lighter. The alpha particle's double charge means it needs only half the potential its mass alone would suggest, which is why the factor of 2 multiplies the mass ratio.
Q4 · Physics · Dual Nature of Matter and Radiation
Light of wavelength λ falling on a metal surface gives a stopping potential of 3V₀. Light of wavelength 2λ gives a stopping potential of V₀. What is the threshold wavelength of the metal?
Answer: (B)
hc/λ = φ + 3eV₀ and hc/2λ = φ + eV₀. Subtracting, hc/2λ = 2eV₀, so eV₀ = hc/4λ. Then φ = hc/2λ − hc/4λ = hc/4λ, and the threshold wavelength is hc/φ = 4λ.
Q5 · Physics · Dual Nature of Matter and Radiation
A proton and an alpha particle (mass ≈ 4 times the proton mass, charge = 2e) are each accelerated from rest through different potential differences, V_p for the proton and V_α for the alpha particle. Both end up with the same de Broglie wavelength. Treating both as non-relativistic, what is the ratio V_p : V_α?
Answer: (A)
A particle of charge q accelerated through V gains kinetic energy qV, so its momentum is p = √(2mqV) and its wavelength is λ = h/√(2mqV). Equal wavelengths require equal momenta, so m_p q_p V_p = m_α q_α V_α. Substituting m_α = 4m_p and q_α = 2q_p gives V_p = (4 × 2) V_α = 8V_α. The ratio V_p : V_α is therefore 8 : 1.
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All 20 real JEE Advanced questions from Dual Nature of Matter and Radiation.
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About Dual Nature of Matter and Radiation in JEE Advanced.
How many questions come from Dual Nature of Matter and Radiation in JEE Advanced?
Dual Nature of Matter and Radiation (Physics, Class 12) has been asked 20 times in the 40 JEE (Advanced) papers from 2007–2026: about 0.5 questions a paper, 3% of all Physics questions. It is the 16th most-asked of 19 Physics chapters. The two 2026 papers had 0 from it.
Which topics of Dual Nature of Matter and Radiation are asked most in JEE Advanced?
Photoelectric effect (11), de Broglie wavelength (9), counted over the papers from 2007–2026.
Is Dual Nature of Matter and Radiation important for JEE Advanced 2027?
It is in the syllabus in force, so it can be asked. By past papers it ranks 16 of 19 in Physics; use that to decide how much time it gets, not whether to study it.
Where can I solve Dual Nature of Matter and Radiation JEE Advanced previous year questions?
On Nikaalle, free: sign up and practise every past JEE Advanced question from Dual Nature of Matter and Radiation with an explanation for each, or sit the full papers timed. The ten questions on this page are our own, written in the same pattern.
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