NEET UG · Physics · Dual Nature of Radiation and Matter

Photoelectric Effect: NEET previous year questions

20 questions in ten years of NEET, in 10 of 10 papers. Pattern: Every year. Here is how it is asked and which ideas come back.

Asked in 10 years: 20; about 1.9 per paper
Years asked: 10/10; last asked 2026
Chance of a question next paper: 84%; historical rate, how we compute it
Weighted estimate: 2.1; model; history: 1.9 a paper on average, typically 1–3

Key findings

01
Asked in 10 of 10 papers, 20 questions in all: #12 of 204 topics by ten-year total.
02
63% of its questions since 2018 tested an idea never asked before; 4 repeated an idea from the year before.
03
The most repeated idea is de Broglie Wavelength of Particles, asked 4 times (2017, 2018, 2022, 2024), usually as “numerical”.
04
NEET has asked 11 of the 88 ideas in this topic; 72 have never been asked, directly or indirectly.
05
Mostly asked as numerical (40%); 45% easy, 0% hard, and up from 1.8 to 2.3 questions a paper since 2024.

Questions per year

Up to 2023: 1.8; per paper
Since 2024: 2.3; +0.5
Usual gap: 1.0 yrs; between papers asking it
Swing: ±0.6; questions, year to year

Recent framings

numerical: momentum ratio of electron and photon
compare stopping potentials by threshold wavelength
effect of frequency and intensity on photocurrent

Revise first

Photon Momentum and Effective Mass (2024 2025 2026); Effect of Intensity vs. Frequency (2025 2026); Threshold Wavelength Condition (2020 2026)

How it is asked

Difficulty, format and skill

Across all 20 questions on Photoelectric Effect since 2017.

Difficulty

QUESTIONS

911

Easy9 · 45%
Medium11 · 55%
Hard0 · 0%

Format

Numerical · 8 Q40%
One-line MCQ · 7 Q35%
Figure-based · 4 Q20%
Other · 1 Q5%

Skill tested

Calculation · 6 Q30%
Multi-step · 5 Q25%
Data or graph · 4 Q20%
Application · 3 Q15%
Concept · 2 Q10%

Repeats

New idea, or one asked before?

Each column is a paper. Blue questions tested an idea NEET had not asked before; navy ones went back to an idea from an earlier paper. 2017 is the first paper, so everything in it counts as new.

’17’18’19’20’21’22’23’24’25’26

Idea asked for the first time
Idea asked in an earlier paper

Coverage of the topic

NEET has asked 11 of the 88 ideas in this topic. 72 have never been asked yet.

1172

Asked directly11 · 13%
Touched inside another question5 · 6%
Never asked72 · 82%

Ideas come from Lumi’s syllabus map of NCERT. A never-asked idea is not a safe skip: most new questions come from exactly these.

Drill down

Idea, year, question

Every idea NEET tested in this topic, with its ten papers. Open one to read the questions.

ideaAskedShareYears’17’18’19’20’21’22’23’24’25’26

Repeated4 · 20%20%4/10
- 2024 · Q34
  The graph which shows the variation of $\left(\frac{1}{\lambda^2}\right)$ and its kinetic energy, $E$ is (where $\lambda$ is de Broglie…
  mediumFigure-based
- 2022 · Q30
  The graph which shows the variation of the de Broglie wavelength ( $\lambda$ ) of a particle and its associated momentum (p) is :
  easyFigure-based
- 2018 · Q12
  An electron of mass m with an initial velocity $\vec{V} = V_0\hat{i}$ ( $V_0 > 0$ ) enters an electric field $\vec{E} = -E_0\hat{i}$ ( $E_0$ …
  mediumNumericalAsked the year before
- 2017 · Q6
  The de-Broglie wavelength of a neutron in thermal equilibrium with heavy water at a temperature T (Kelvin) and mass m, is :
  mediumOne-line MCQNew idea
Repeated3 · 15%15%3/10
Repeated2 · 10%10%2/10
Repeated2 · 10%10%2/10
1 · 5%5%1/10
1 · 5%5%1/10
1 · 5%5%1/10
1 · 5%5%1/10
1 · 5%5%1/10
1 · 5%5%1/10
1 · 5%5%1/10
1 · 5%5%1/10
1 · 5%5%1/10

Squares are the ten papers, 2017 to 2026; darker means more questions. Share is of the level above.

Ideas

Every idea inside this topic

13 different ideas were tested; 4 came more than once. Work Function and Threshold is the foundation for 61 other ideas in the syllabus.

de Broglie Wavelength of Particles4×
numerical
Figure-based · 6% next
Photon Momentum and Effective Mass3×
count correct statements on photon properties
Numerical · 11% next · foundation for 6
Effect of Intensity vs. Frequency2×
effect of frequency and intensity on photocurrent
Figure-based · 11% next · foundation for 2
Threshold Wavelength Condition2×
effect of frequency and intensity on photocurrent
One-line MCQ · 6% next
Inverse Photoelectric Effect1×
proportionality of x-ray cutoff wavelength to voltage
One-line MCQ · 4% next
Work Function and Threshold1×
identify metals emitting photoelectrons
One-line MCQ · 4% next · foundation for 61
Solving Two-State Photoelectric Equations1×
numerical
Numerical · 4% next
De Broglie Wavelength of Emitted Photoelectron1×
relation of wavelengths for emitted photoelectron
One-line MCQ · 4% next
Photon Emission Rate from Power1×
numerical
Numerical · 4% next · foundation for 3
de Broglie Wavelength of Accelerated Electrons1×
numerical
Numerical · 4% next
eV to Joule Conversion in Photoelectric Equations1×
numerical
Numerical · 4% next
De Broglie Wavelength of Photoelectron1×
numerical
Numerical · 4% next
Maximum Velocity of Photoelectrons1×
numerical
Numerical · 4% next · foundation for 2

Idea	Times	Format	Chance next	Foundation for
de Broglie Wavelength of Particlesnumerical	4	Figure-basedData or graph	6%	–
Photon Momentum and Effective Masscount correct statements on photon properties	3	NumericalCalculation	11%	6 ideas
Effect of Intensity vs. Frequencyeffect of frequency and intensity on photocurrent	2	Figure-basedData or graph	11%	2 ideas
Threshold Wavelength Conditioneffect of frequency and intensity on photocurrent	2	One-line MCQApplication	6%	–
Inverse Photoelectric Effectproportionality of x-ray cutoff wavelength to voltage	1	One-line MCQConcept	4%	–
Work Function and Thresholdidentify metals emitting photoelectrons	1	One-line MCQApplication	4%	61 ideas
Solving Two-State Photoelectric Equationsnumerical	1	NumericalMulti-step	4%	–
De Broglie Wavelength of Emitted Photoelectronrelation of wavelengths for emitted photoelectron	1	One-line MCQMulti-step	4%	–
Photon Emission Rate from Powernumerical	1	NumericalCalculation	4%	3 ideas
de Broglie Wavelength of Accelerated Electronsnumerical	1	NumericalCalculation	4%	–
eV to Joule Conversion in Photoelectric Equationsnumerical	1	NumericalCalculation	4%	–
De Broglie Wavelength of Photoelectronnumerical	1	NumericalCalculation	4%	–
Maximum Velocity of Photoelectronsnumerical	1	NumericalCalculation	4%	2 ideas

Chance next is the historical rate at which an idea with this record came back in the following paper. It is low for every idea, which is why learning the topic beats memorising past questions. All repeated ideas

Every question

Photoelectric Effect questions, year by year

The opening words of each question as it appeared in the official paper, with the idea it tested.

NEET 20263 questions

Q8
A beam of light falls on a metal surface such that photo-electrons are generated. If power of the light source starts to decrease linearly…
Idea: Effect of Intensity vs. Frequency
Asked last yearMediumFigure-based · figure
Q18
A ray of light with wavelength $\lambda$ is incident on three different photo-electric cells namely 1, 2 and 3. The threshold wavelength…
Idea: Threshold Wavelength Condition
MediumOne-line MCQ
Q19
A photon and an electron, each of 20 eV energy, move in free space. The ratio of linear momentum of electron $p_e$ to that of photon…
Idea: Photon Momentum and Effective Mass
Asked last yearMediumNumerical

NEET 20252 questions

Q37
A photon and an electron (mass $m$ ) have the same energy $E$ . The ratio ( $\lambda_{photon}/\lambda_{electron}$ ) of their de Broglie…
Idea: Photon Momentum and Effective Mass
Asked last yearMediumOne-line MCQ
Q38
Which of the following options represent the variation of photoelectric current with property of light shown on the x-axis? A. [graph:…
Idea: Effect of Intensity vs. Frequency
New ideaMediumFigure-based · figure

NEET 20242 questions

Q10
If $c$ is the velocity of light in free space, the correct statements about photon among the following are : A. The energy of a photon is…
Idea: Photon Momentum and Effective Mass
New ideaEasyOther
Q34
The graph which shows the variation of $\left(\frac{1}{\lambda^2}\right)$ and its kinetic energy, $E$ is (where $\lambda$ is de Broglie…
Idea: de Broglie Wavelength of Particles
MediumFigure-based · figure

NEET 20232 questions

Q1
The work functions of Caesium (Cs), Potassium (K) and Sodium (Na) are 2.14 eV, 2.30 eV and 2.75 eV respectively. If incident…
Idea: Work Function and Threshold
New ideaEasyOne-line MCQ
Q22
The minimum wavelength of $X$ -rays produced by an electron accelerated through a potential difference of $V$ volts is proportional to:
Idea: Inverse Photoelectric Effect
New ideaEasyOne-line MCQ

NEET 20222 questions

Q30
The graph which shows the variation of the de Broglie wavelength ( $\lambda$ ) of a particle and its associated momentum (p) is :
Idea: de Broglie Wavelength of Particles
EasyFigure-based · figure
Q31
When two monochromatic lights of frequency, $\nu$ and $\frac{\nu}{2}$ are incident on a photoelectric metal, their stopping potential…
Idea: Solving Two-State Photoelectric Equations
New ideaMediumNumerical

NEET 20212 questions

Q24
The number of photons per second on an average emitted by the source of monochromatic light of wavelength 600 nm, when it delivers the…
Idea: Photon Emission Rate from Power
New ideaEasyNumerical
Q26
An electromagnetic wave of wavelength ' $\lambda$ ' is incident on a photosensitive surface of negligible work function. If 'm' mass is of…
Idea: De Broglie Wavelength of Emitted Photoelectron
New ideaMediumOne-line MCQ

NEET 20203 questions

Q157
Light of frequency 1.5 times the threshold frequency is incident on a photosensitive material. What will be the photoelectric current if…
Idea: Threshold Wavelength Condition
New ideaEasyOne-line MCQ
Q159
The energy required to break one bond in DNA is $10^{-20}$ J. This value in eV is nearly :
Idea: eV to Joule Conversion in Photoelectric Equations
New ideaEasyNumerical
Q175
An electron is accelerated from rest through a potential difference of V volt. If the de Broglie wavelength of the electron is…
Idea: de Broglie Wavelength of Accelerated Electrons
New ideaMediumNumerical

NEET 20191 question

Q13
An electron is accelerated through a potential difference of 10,000 V. Its de Broglie wavelength is, (nearly) : $(m_e = 9\times10^{-31}$ kg)
Idea: De Broglie Wavelength of Photoelectron
New ideaEasyNumerical

NEET 20182 questions

Q12
An electron of mass m with an initial velocity $\vec{V} = V_0\hat{i}$ ( $V_0 > 0$ ) enters an electric field $\vec{E} = -E_0\hat{i}$ ( $E_0$ …
Idea: de Broglie Wavelength of Particles
Asked last yearMediumNumerical
Q14
When the light of frequency $2v_0$ (where $v_0$ is threshold frequency), is incident on a metal plate, the maximum velocity of electrons…
Idea: Maximum Velocity of Photoelectrons
New ideaEasyNumerical

NEET 20171 question

Q6
The de-Broglie wavelength of a neutron in thermal equilibrium with heavy water at a temperature T (Kelvin) and mass m, is :
Idea: de Broglie Wavelength of Particles
MediumOne-line MCQ

Questions from the official NEET UG papers published by NTA (CBSE before 2019). Topic and idea tags, counts and notes are Lumi’s.