Modern Physics NEET PYQ Analysis (2015–2025) — The Highest Marks-Per-Hour Chapter in NEET Physics

de Broglie Wavelength Has Been Tested 21 Times in 10 Years. That's Twice Per Paper.

If you had to bet on one concept appearing in your NEET Physics paper, bet on this:

The de Broglie wavelength of an accelerated charge — λ = h/√(2mqV) — has appeared 21 times across 2015 to 2025. That's an average of twice per examination cycle. No other Modern Physics concept comes close. It's tested as a direct numerical, an algebraic ratio, a graphical relationship, and a conceptual comparison between particles.

And here's why Modern Physics deserves a spot at the very top of your revision list: it has the highest marks-per-hour ratio in all of NEET Physics. Unlike Mechanics (spatial visualisation) or Ray Optics (sign conventions and geometry), Modern Physics relies on discrete, quantised algebraic states. The physics is simpler. The only real difficulty is the dimensional scale of the numbers — and we'll give you the shortcut that eliminates that entirely.

We tracked 59 verified questions across Dual Nature, Atoms, and Nuclei from every NEET sitting from 2015 to 2025. The combined unit delivers 4-6 questions per paper — 16 to 24 marks, roughly 10-15% of Physics. This is our fourth Physics PYQ analysis, joining Electrostatics, Current Electricity, and Ray Optics.

🎯 We analyzed every Modern Physics question NTA has asked. The app has them all — ready to play and practice.

Quantum concepts feel abstract until you see them. Logic Bloom's Playground turns Modern Physics into interactive games: fire photons at metal surfaces and watch electrons eject above threshold, drop electrons through Bohr energy levels and see spectral lines appear, watch a radioactive sample halve every half-life. Then practice every PYQ from this analysis — line by line from NCERT + 10 years of PYQs, all mapped to chapter topics. When you're stuck, TarQ teaches the concept. Your Mistake Book catches every eV-to-Joule slip before the exam does.

Get the app → Free to start.

How Many Questions: A Rock-Solid 4-5 Per Paper

Year	Dual Nature	Atoms	Nuclei	Total
2025	2	1	2	5
2024	3	1	1	5
2023	2	1	1	4
2022	2	1	2	5
2021	2	1	1	4
2020	2	1	2	5
2019	2	1	1	4
2018	2	1	1	4
2017	2	1	1	4
2016	2	1	1	4
2015	2	1	1	4

The chapter split is remarkably stable: Dual Nature ~45%, Nuclei ~30%, Atoms ~25%. Dual Nature dominates because the de Broglie wavelength is so versatile — NTA can cross-link it with classical mechanics, electrostatics (accelerating potential), and relativity. This consistency means you can predict the structure of the Modern Physics section before you even open the paper.

Sub-Topic Frequency: de Broglie + Photoelectric = 40% of the Chapter

Sub-topic	Questions (10 yr)	Dominant Format
de Broglie Wavelength	21	Numerical + ratio
Photoelectric Effect	19	Conceptual + graphical
Bohr Model of Atom	14	Numerical (energy levels)
Radioactivity	12	Numerical (decay law)
Photon Properties	9	Conceptual MCQ
Nuclear Composition	7	Numerical (R = R₀A^⅓)
Hydrogen Spectrum	5	Numerical (Rydberg)
Mass-Energy & Binding Energy	5	Conceptual
Nuclear Reactions (fission/fusion)	3	Numerical (Q-value)
Atomic Models (Rutherford scattering)	1	Nearly dormant

de Broglie and Photoelectric Effect together carry 40% of the chapter. Add Bohr Model and Radioactivity, and just four sub-topics account for 78% of all Modern Physics questions. This is the most concentrated, predictable distribution of any Physics chapter.

What's Increasing and What's Dying

Increasing — de Broglie ratio comparisons. The "electron vs photon with the same energy" ratio question has appeared in 2016, 2018, AND 2025. NTA uses it as a high-difficulty separator because it forces students to switch between classical mechanics (electron: E = p²/2m) and relativity (photon: E = pc). Statement-based questions on photon momentum and wave-particle duality have also surged since 2022.

Dying — Rutherford alpha scattering. The historical atomic models (distance of closest approach, impact parameter) are nearly dormant. Heavy binding-energy-curve arithmetic has been replaced by simple conceptual identification (why iron-56 is the stability peak). NTA has moved from "compute the value" to "understand the relationship."

The Format Shift: Raw Arithmetic Down, Algebra and Statements Up

Format	2015–2018	2022–2025
Numerical (calculation)	65%	40%
Conceptual MCQ (algebraic ratios)	25%	35%
Graphical	10%	15%
Assertion-Reason / Statement	0%	10%

The clever shift: NTA now designs questions where the physical constants (h, c) cancel out, forcing you to derive a ratio rather than compute a scalar. A question like "ratio of de Broglie wavelengths of an electron and photon with the same energy" has no messy numbers — it's pure algebra. This punishes rote calculators and rewards conceptual understanding.

🎯 The 1240 shortcut: never multiply 6.63×10⁻³⁴ by 3×10⁸ again.

Instead of dealing with massive exponents, memorise this: hc ≈ 1240 eV·nm. If wavelength is in nanometres, photon energy in eV = 1240/λ. A 620 nm photon? 1240/620 = 2 eV. Instantly. This single shortcut eliminates the #1 source of Modern Physics calculation fatigue and the eV-to-Joule conversion trap. Logic Bloom's Playground drills these shortcuts through games until they're automatic — with TarQ showing you exactly when to deploy each one. Then practice every PYQ and let your Mistake Book catch the conversion errors.

Play the shortcuts → Free to start.

The 4 Modern Physics Traps NTA Exploits Every Year

📌 4 Documented Traps — Know Them, Dodge Them
1. The eV vs Joule Trap The #1 error NTA targets	Calculating hc/λ in SI units gives Joules, but work function is given in eV. Students equate them directly without converting (1 eV = 1.6×10⁻¹⁹ J). NTA builds the un-converted wrong answer into the options. Fix: use hc = 1240 eV·nm so everything stays in eV.
2. The Frequency vs Wavelength Threshold Trap Tested 2026 cancelled, others	Emission requires frequency ν > ν₀ (threshold) BUT wavelength λ < λ₀. The inverse relationship traps students. When asked "which wavelength does NOT cause emission," the answer is the LONGEST wavelength (lowest energy), not the shortest.
3. The Z² Bohr Trap Tested for He⁺, Li²⁺	For hydrogen-like ions (He⁺, Li²⁺), energy = −13.6 × Z²/n² eV. Students forget the Z² and use the plain hydrogen formula. He⁺ energies are 4× hydrogen (Z=2), Li²⁺ are 9× (Z=3).
4. The Excited State Numbering Trap Tested 2023 Manipur	"Second excited state" means n = 3 (ground = n=1, first excited = n=2, second excited = n=3). Students read "second" and use n = 2. This single misread flips the entire energy calculation.

The Photoelectric Effect: Intensity vs Frequency — The Eternal Trap

NTA tests one conceptual distinction relentlessly: what depends on intensity vs what depends on frequency.

Quantity	Depends On	Independent Of
Max kinetic energy of photoelectrons	Frequency (and work function)	Intensity
Stopping potential	Frequency (and work function)	Intensity
Photoelectric current	Intensity (number of photons)	Frequency (above threshold)
Whether emission happens at all	Frequency > threshold	Intensity entirely

The killer fact: If light is below threshold frequency, NO intensity — however high — will cause emission. NTA tested this in 2020 Phase 2: "frequency halved and intensity doubled → current?" Answer: zero (below threshold, no emission regardless of intensity).

The Bohr Model: Memorise These 4 Energy Levels

Don't recalculate Bohr energies during the exam. Memorise the first four levels of hydrogen and transitions become instant mental math:

🎯 Hydrogen Energy Levels — Memorise These Cold
n = 1 (ground state)	−13.6 eV
n = 2 (first excited)	−3.4 eV
n = 3 (second excited)	−1.51 eV
n = 4 (third excited)	−0.85 eV

Key proportionalities: Radius rₙ ∝ n²/Z. Velocity vₙ ∝ Z/n. Energy Eₙ ∝ −Z²/n². For hydrogen-like ions, multiply energy by Z² (He⁺ = ×4, Li²⁺ = ×9). The transition n=4 → n=2 releases (3.4 − 0.85) = 2.55 eV — no calculator needed if you know the levels.

Radioactivity: The Half-Life Fraction Shortcuts

🎯 Decay Fraction Shortcuts — Skip the Logarithm
% Remaining	Fraction	Half-lives elapsed
50%	1/2	1
25%	1/4	2
12.5%	1/8	3
6.25%	1/16	4

The 2020 trap: "Half-life 10 min, 600 nuclei initially, time for 450 to disintegrate?" Students use 450 as the remaining count. But 450 disintegrated means 150 remain = 1/4 of 600 = 2 half-lives = 20 minutes. Always check whether the question gives decayed or remaining nuclei.

Half-life vs mean life: Half-life T₁/₂ = 0.693/λ. Mean life τ = 1/λ. Students substitute one for the other. They differ by a factor of 0.693 — and NTA puts both wrong answers in the options.

Cross-Chapter Connections

Cross-Chapter Link	What It Tests	Example
Modern Physics + Ray Optics	Photon energy and EM spectrum	Calculate transition energy → identify spectral region (UV, visible, IR)
Modern Physics + Electrostatics	Accelerated charge: K = qV fused with de Broglie	λ = h/√(2mqV) — the accelerating potential comes straight from electrostatics
Modern Physics + Current Electricity	Photoelectric current as circuit element	Photon flux (intensity) ∝ photocurrent — the vacuum tube is a circuit
Modern Physics + Semiconductor Electronics	Band gap as threshold energy	Photodiode/LED band gap Eg acts as the work function for emission/absorption

Re-NEET 2026 / NEET 2027 Predictions

Top 5 Sub-Topics Most Likely to Appear

#	Predicted Topic	Why It's Due
1	de Broglie wavelength ratios (different particles, same V)	Tested 21 times. Expect a ratio between alpha particle and proton under identical accelerating potential, testing mass/charge dependence in λ = h/√(2mqV).
2	Einstein's photoelectric equation with eV conversion	Given wavelength → find max KE. High likelihood of an eV-vs-Joule conversion trap. Use the 1240 shortcut.
3	Bohr transition energies for hydrogen-like ions	Excitation energy of He⁺ or Li²⁺ — heavily testing the Z² dependence students forget.
4	Radioactive decay fractions	"Time for 87.5% to decay" = 3 half-lives (12.5% = 1/8 remains). Conceptual framing to test if students recognise the fraction shortcut.
5	Nuclear radius ratio in asymmetric fission	R = R₀A^⅓. Given a nucleus splitting into two daughters, find the ratio of radii via cube roots of mass numbers.

3 Concepts Due for a Return

Concept	Last Tested	Likely Format
Distance of closest approach (Rutherford)	Dormant several cycles	Equate initial KE to electrostatic PE: K = (1/4πε₀)(2Ze²/r₀). Cross-links to electrostatics.
Hydrogen spectrum series limits	Rarely tested recently	Calculate shortest/longest wavelength in Balmer or Lyman series using Rydberg formula.
Alpha/beta decay chain balancing	~2021	Track A and Z through successive α and β⁻ decays to identify the final stable isotope.

Modern Physics NEET PYQs (2015–2025) — 12 Questions You Must Attempt

These 12 questions represent the core of NTA's Modern Physics testing. Each tests a concept repeated multiple times. For each, we explain the specific NTA trap — the mistake that costs you 5 marks (4 lost + 1 negative).

📌 12 Must-Attempt Modern Physics PYQs — With the NTA Trap Explained
1. de Broglie Ratio Trap (2025/2018/2016)	A photon and electron (mass m) have the same energy E. Ratio of de Broglie wavelength of photon to electron? Answer: c√(2m/E). Trap: Using classical E = p²/2m for the photon. Photon is relativistic (E = pc → λ = hc/E). Electron is classical (λ = h/√(2mE)). NTA repeated this 3 times.
2. Intensity Misdirection (2023)	Max kinetic energy of photoelectrons is independent of which factor? Answer: Intensity of incident radiation. Trap: Confusing photocurrent (depends on intensity) with kinetic energy (depends only on frequency).
3. Threshold Wavelength Reversal (2026 cancelled)	Work function 6.6 eV. Which wavelength does NOT cause emission: 200, 150, 100, 50 nm? Answer: 200 nm. Trap: Emission needs λ < threshold (187.5 nm). The LONGEST wavelength (200 nm, lowest energy) is the one that fails. Students pick the shortest.
4. Accelerated Electron de Broglie (2023)	de Broglie wavelength of an electron accelerated through 81 V? Answer: 0.136 nm. Trap: Doing the full h/√(2mqV) calculation. Use the shortcut: λ = 1.227/√V nm = 1.227/9 = 0.136 nm.
5. Disintegration Fraction (2020)	Half-life 10 min, 600 nuclei initially. Time for 450 nuclei to disintegrate? Answer: 20 min. Trap: Using 450 as remaining. 450 disintegrated → 150 remain = 1/4 = 2 half-lives = 20 min.
6. Bohr Constant Force (2025)	Particle under constant force F (not Coulombic). How do radius and velocity depend on n? Answer: r ∝ n^(2/3), v ∝ n^(1/3). Trap: Blindly using hydrogen's r ∝ n², v ∝ 1/n. Must rederive from mv²/r = F (constant) with mvr = nh/2π.
7. Work Function Algebra (2024)	Work function Φ eV, light of wavelength λ = hc/e metres. Max KE? Answer: e − Φ. Trap: Panic from variable substitution. Sub λ = hc/e into KE = hc/λ − Φ → KE = e − Φ.
8. Nuclear Radius Ratio (2022)	Nucleus of mass 189 splits into masses 125 and 64. Ratio of radii? Answer: 5:4. Trap: Taking direct or square-root ratio of masses. R ∝ A^(1/3), so ratio = 125^⅓ : 64^⅓ = 5:4.
9. Photon Property Negation (2024)	Which statement about a photon is INCORRECT? Answer: "Photon possesses positive charge." Trap: Assuming photons have charge because they interact with electrons. Photons are neutral.
10. The 1/λ² Graph (2024)	Graph of 1/λ² vs kinetic energy E for a free particle? Answer: Straight line through origin. Trap: Picking a curve. Square λ = h/√(2mE) → 1/λ² = (2m/h²)E, which is linear.
11. Ionisation from Excited State (2023 Manipur)	Energy to ionise hydrogen from its second excited state? Answer: 1.51 eV. Trap: Second excited state = n=3 (not n=2). Energy at n=3 is −1.51 eV, so ionisation needs +1.51 eV.
12. Wavelength Hierarchy (2024)	Electron and alpha particle accelerated by same potential. Compare de Broglie wavelengths. Answer: λₑ > λα. Trap: Thinking the alpha's larger charge wins. The electron's tiny mass dominates √(2mqV), giving it the larger wavelength.

🎯 These are 12 of the 200+ Modern Physics PYQs in the app. Drill all of them.

Every question above is inside Logic Bloom — along with hundreds more from NCERT + 10 years of PYQs, mapped into chapter topics you can learn and master. Play through the simulations first: fire photons at metals, drop electrons through energy levels, watch samples decay. When you get a question wrong, TarQ teaches you the concept — not the answer. Your Mistake Book tracks exactly which traps catch you — eV conversions, Z² omissions, excited-state misreads. Then take it all into Battleground — 1v1 duels under real exam pressure. Get Logic Bloom — Free to start →

The 15 Formulas You Must Know Cold

🎯 15 Exam-Critical Formulas — Each Has Been Tested
1.	Photon energy: E = hν = hc/λ	Use hc = 1240 eV·nm for instant eV answers.
2.	Photoelectric: K_max = hc/λ − Φ = eV₀	V₀ = stopping potential. Slope of V₀ vs ν graph = h/e.
3.	de Broglie (momentum): λ = h/p = h/mv	Basic matter wave definition.
4.	de Broglie (KE): λ = h/√(2mK)	For a particle with kinetic energy K.
5.	de Broglie (accelerated): λ = h/√(2mqV)	Tested 21 times. The single most important formula.
6.	Electron shortcut: λ = 1.227/√V nm = √(150/V) Å	Skip the full calculation for accelerated electrons.
7.	Bohr radius: rₙ = 0.529 × n²/Z Å	Radius grows as n².
8.	Bohr velocity: vₙ = 2.18×10⁶ × Z/n m/s	Velocity drops as 1/n.
9.	Bohr energy: Eₙ = −13.6 × Z²/n² eV	Don't forget Z² for He⁺, Li²⁺.
10.	Rydberg: 1/λ = RZ²(1/n₁² − 1/n₂²)	R = 1.097×10⁷ m⁻¹.
11.	Nuclear radius: R = R₀A^(1/3)	R₀ = 1.2 fm. Ratio of radii = cube root of mass ratio.
12.	Mass-energy: E = Δm·c² = Δm(amu)×931.5 MeV	1 amu = 931.5 MeV.
13.	Decay law: N = N₀e^(−λt)	For non-integer half-lives.
14.	Half-life: T₁/₂ = 0.693/λ	Mean life τ = 1/λ. Don't confuse them.
15.	Remaining nuclei: N = N₀(½)ⁿ, n = t/T₁/₂	For integer half-lives — use the fraction shortcuts.

How to Prepare Based on the Data

📌 Data-Driven Preparation Strategy for Modern Physics NEET 2027
Master de Broglie in all 5 forms	Momentum, kinetic energy, accelerated charge, electron shortcut, and ratio comparisons. This single concept appears twice per paper. The accelerated-charge form λ = h/√(2mqV) is the most tested formula in the entire chapter.
Memorise the 1240 shortcut and the 4 Bohr energy levels	hc = 1240 eV·nm eliminates the eV-conversion trap. The hydrogen levels (−13.6, −3.4, −1.51, −0.85) make every transition instant mental math. These two memorisations alone solve half the chapter.
Drill the intensity-vs-frequency distinction	Kinetic energy and stopping potential depend on frequency only. Photocurrent depends on intensity only. Below threshold, no intensity causes emission. This conceptual fact is tested almost every year.
Learn the decay fraction shortcuts	50%=1 half-life, 25%=2, 12.5%=3, 6.25%=4. And always check: does the question give decayed or remaining nuclei? The 2020 question trapped everyone who used the decayed count as remaining.
Know the 4 traps by name	eV-vs-Joule, frequency-vs-wavelength threshold, the Z² omission, and the excited-state numbering. Each has appeared in real papers. Recognising the trap before you read the options makes you immune.
Play the physics, practice every PYQ, track your mistakes	Logic Bloom's Playground turns Modern Physics into interactive games — fire photons above and below threshold, drop electrons through Bohr levels and watch spectral lines form, halve a radioactive sample in real time — with TarQ guiding the concept. Then practice every PYQ: line by line from NCERT + 10 years of PYQs, all mapped to chapter topics. Your Mistake Book catches eV conversions, Z² omissions, and half-life confusions. Then take it into Battleground — 1v1 duels under real exam pressure. Free to start.

Done analysing? Now play, understand, and master.

🎯 4-5 questions per paper. de Broglie tested 21 times. Highest marks-per-hour in NEET Physics. The patterns are here. The practice is in the app.
🎮 Playground Understand through games — with TarQ	Every quantum concept as an interactive game — fire photons at metals and watch the photoelectric threshold, drop electrons through Bohr energy levels and see spectral lines, watch a radioactive sample halve every half-life. Chapter maps break each topic into concept games → readings → MCQs. Line by line from NCERT + 10 years of PYQs, all inside. When you're stuck, TarQ teaches the concept. Mistake Book catches conversion errors before the exam does. Get the app →
⚔️ Battleground Score through practice — 1v1 duels	Take the concepts you understood in Playground and test them under real time pressure. Challenge a friend or get matched live. 10 timed questions per match across Physics, Chemistry, Biology. ELO climbs through 6 tiers: Bronze → Silver → Gold → Platinum → Diamond → Archeon. Get the app →
Understand through games. Score through practice. Get Logic Bloom — Free to start →

FAQs — Modern Physics NEET PYQ

Q1: How many questions come from Modern Physics in NEET?
Modern Physics (Dual Nature + Atoms + Nuclei) delivers 4-6 questions per paper — 16 to 24 marks, roughly 10-15% of Physics. The split is consistent: Dual Nature ~45%, Nuclei ~30%, Atoms ~25%. It has the highest marks-per-hour ratio of any Physics chapter.

Q2: What is the most tested concept in Modern Physics?
The de Broglie wavelength of an accelerated charge — λ = h/√(2mqV) — has appeared 21 times in 10 years, averaging twice per paper. It's tested as direct numericals, algebraic ratios, graphical relationships, and particle comparisons. Master this one formula above all others.

Q3: What is the 1240 shortcut?
hc ≈ 1240 eV·nm. If wavelength is in nanometres, photon energy in eV = 1240/λ. A 620 nm photon has energy 1240/620 = 2 eV instantly. This eliminates the massive-exponent calculations and the eV-to-Joule conversion trap that NTA exploits most.

Q4: Does intensity affect the kinetic energy of photoelectrons?
No. Maximum kinetic energy and stopping potential depend ONLY on frequency (and work function), never on intensity. Intensity affects only the photocurrent (number of electrons emitted). Below threshold frequency, no intensity — however high — causes any emission at all.

Q5: Are there actual Modern Physics PYQ questions to practice?
Yes — this article contains 12 representative PYQs with the NTA trap explained for each. For the full set of 200+ Modern Physics PYQs, mapped to chapter topics with TarQ teaching and a Mistake Book tracking your errors, download Logic Bloom. Free to start.