NEET PhysicsUpdated 19 Oct 2026

Dual Nature of Radiation and Matter: NEET PYQs and weightage

Dual Nature of Radiation and Matter carries 5.3 of 100 Physics marks in NEET by past-paper share: 40 of the 758 tagged NEET Physics PYQs in the ViJEEta bank (NEET 2013–2026). It ranks 3 of 30 Physics chapters.

Take the 25-question Dual Nature of Radiation and Matter test Formula sheet ↓All NEET Physics chapters

5.3/100 Weight in Physics

Exam importance (4/5, by past-paper share)

40 NEET PYQs

224 Practice questions

197 With measured difficulty

How the weight is computed: this chapter's tagged NEET PYQs divided by all tagged NEET Physics PYQs in the bank (40 of 758), times 100, with repeated questions counted once. The bank does not store the year of each NEET question, so none is printed. Computed from the bank at build time. Updated 19 Oct 2026.

Dual Nature of Radiation and Matter: formula sheet for NEET

13 formulas, each with when to use it. Copy it onto one page of your notebook: that page is this chapter's handbook.

Einstein's photoelectric equation
$K_{m a x} = h ν - ϕ_{0}$
Use it when: You know the light's frequency and the metal's work function and need the fastest electron's energy.
Stopping potential
$e V_{0} = K_{m a x} = \frac{1}{2} m v_{m a x}^{2}$
Use it when: You need to convert between cut-off voltage and maximum KE or maximum speed ( $V_{0}$ in volts gives $K_{m a x}$ directly in eV).
Photon energy
$E = h ν = \frac{h c}{λ}$
Use it when: The question gives frequency or wavelength and asks for the energy of one photon.
Threshold frequency
$ν_{0} = \frac{ϕ _{0}}{h}$
Use it when: You need the lowest frequency that can eject electrons (below $ν_{0}$ nothing comes out, however bright the light).
Threshold form of Einstein's equation
$\frac{1}{2} m v_{m a x}^{2} = e V_{0} = h (ν - ν_{0})$
Use it when: You are given the threshold frequency instead of the work function.
V0 vs frequency straight line
$V_{0} = \frac{h}{e} ν - \frac{ϕ _{0}}{e} (valid for ν \geq ν_{0})$
Use it when: A graph is given. Slope $= h / e$ is the same for every metal, and the line cuts the $ν$ -axis at $ν_{0}$ .
Wavelength from stopping potential
$λ = \frac{h c}{e V _{0} + ϕ _{0}}$
Use it when: You know $V_{0}$ and $ϕ_{0}$ and need the wavelength of the incident light.
Photon momentum
$p = \frac{h ν}{c} = \frac{h}{λ}$
Use it when: You need the momentum carried by one photon of known $λ$ or $ν$ .
de Broglie wavelength
$λ = \frac{h}{p} = \frac{h}{m v}$
Use it when: Any moving particle (electron, proton, ball) is involved. A heavier or faster particle has a smaller $λ$ .
Photons per second
$N = \frac{P}{E} (since P = N E)$
Use it when: A source's power is given and you need the number of photons emitted per second.
Intensity rule
$saturation current \propto intensity$
$V_{0}$ and $K_{m a x}$ do not depend on intensity.
Use it when: A question changes only the brightness of light at a fixed frequency.
Electron volt
$1 eV = 1.602 \times 1 0^{- 19} J$
Use it when: Work function or KE is in eV but $h$ is in J s. Convert before dividing.
Planck's constant
$h = 6.626 \times 1 0^{- 34} J s$
Use it when: You need a numerical value of $E$ , $ν_{0}$ , $p$ or $λ$ ( $V_{0}$ – $ν$ slope $\times e$ also gives $h$ ).

Trap

Brighter light does not give faster electrons. Intensity only changes how many electrons come out (the photocurrent). K_max and V₀ change only with frequency and the metal.

How does NEET ask Dual Nature of Radiation and Matter?

8 real previous-year questions from this chapter, as printed in the paper, each with its worked solution. Answer the first one here with no sign-in.

Q1PhysicsNEET UG PYQPhotoelectric Effect

Try right here · No sign-in

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 electromagnetic radiation has an incident energy of 2.20 eV, which of these photosensitive surfaces may emit photoelectrons ?

Answer key (D) & worked solution

Correct answer: Option D

Given energy of photon

E = 2.20

eV Work function of Cs

ϕ_{0} = 2.14 e V, K ϕ_{0} = 2.30 e V, N a ϕ_{0} = 2.75 e V

We know that

\overset{e}{ˉ}

emits when

h v > ϕ_{0}

Here it is clear that energy of photon is more than work function of

C s

[Caesium] only so answer only (

C s

Q2PhysicsNEET UG PYQWave Nature of Matter

Electrons of mass m with de-Broglie wavelength

λ

fall on the target in an X-ray tube. The cutoff wavelengths

(λ_{0})

of the emitted X - ray is

λ_{0} = \frac{2 h}{m c}

λ_{0} = \frac{2 m ^{2} c ^{2} λ ^{3}}{h ^{2}}

λ_{0} = λ

λ_{0} = \frac{2 m c λ ^{2}}{h}

Answer key (D) & worked solution

Correct answer: Option D

λ = \frac{h}{p} \Rightarrow p = \frac{h}{λ}

E = \frac{p ^{2}}{2 m} = \frac{h ^{2}}{2 m λ ^{2}}

Also in X - r a y, E = \frac{h c}{λ _{0}}

∴ \frac{h c}{λ _{0}} = \frac{h ^{2}}{2 m λ ^{2}} \Rightarrow λ_{0} = \frac{2 m c λ ^{2}}{h}

Q3PhysicsNEET UG PYQWave Nature of Matter

An electron is accelerated from rest through a potential difference of V volt. If the de-Broglie wavelength of the electron is

1.227 \times 1 0^{- 2}

nm, the potential difference is:

1 0^{3} V

1 0^{4} V

C10 V

1 0^{2} V

Answer key (B) & worked solution

Correct answer: Option B

For

e^{-},

according to de-broglie’s wavelength

λ = \frac{12.27}{V} A 0

λ = \frac{12.27}{V} \times 1 0^{- 10}

= 1.227 \times 1 0^{- 2} \times 1 0^{- 9}

\frac{1}{V} = \frac{1}{100} \Rightarrow V = 1 0^{4} V

Q4PhysicsNEET UG PYQWave Nature of Matter

An electron of mass m and a photon have same energy E. The ratio of de-Broglie wavelengths associated with them is.

\frac{1}{c} (\frac{E}{2 m})^{\frac{1}{2}}

(\frac{E}{2 m})^{\frac{1}{2}}

c (2 m E)^{\frac{1}{2}}

\frac{1}{c} (\frac{2 m}{E})^{\frac{1}{2}}

Answer key (A) & worked solution

Correct answer: Option A

For electron

λ_{e} = \frac{h}{2 m E}

For photon E = pc

\Rightarrow λ_{P h} = \frac{h c}{E} \Rightarrow \frac{λ _{e}}{λ _{P h}} = \frac{h}{2 m E} \times \frac{E}{h c} = (\frac{E}{2 m})^{\frac{1}{2}} \frac{1}{c}

Q5PhysicsNEET UG PYQPhotoelectric Effect

Light of frequency 1.5 times the threshold frequency is incident on a photosensitive material. What will be the photoelectric current if the frequency is halved and intensity is doubled ?

Aone-fourth

Bzero

Cdoubled

Dfour times

Answer key (B) & worked solution

Correct answer: Option B

Let

f_{o}

be the thershold frequency

f_{0} < f_{1}

f_{1} = 1.5 f_{0}

∴ f_{2} = 0.75 f_{0}

for given condition

f_{incident} < f_{o}

so no photo electron emission i = 0

Q6PhysicsNEET UG PYQPhotons

The minimum wavelength of X-rays produced by an electron accelerated through a potential difference of V volts proportional to:

\frac{1}{V}

\frac{1}{V}

V^{2}

V

Answer key (A) & worked solution

Correct answer: Option A

Minimum wavelength of X-Rays is

λ_{m i n} = \frac{h C}{e V}

Hence

λ_{m i n} \propto \frac{1}{V}

So Ans

(\frac{1}{V})

Q7PhysicsNEET UG PYQEinstein's Photoelectric Equation

When the light of frequency 2v

_{0}

(where v

_{0}

is threshold frequency), is incident on a metal plate, the maximum velocity of electrons emitted is v

_{1}

. When the frequency of the incident radiation is increased to 5v

_{0}

, the maximum velocity of electrons emitted from the same plate is v

_{2}

. The ratio of v

_{1}

to v

_{2}

A4 : 1

B1 : 4

C1 : 2

D2 : 1

Answer key (C) & worked solution

Correct answer: Option C

E = W_{0} + \frac{1}{2} m v^{2}

h (2 v_{0}) = h v_{0} + \frac{1}{2} m v_{1}^{2}

h v_{0} = \frac{1}{2} m v_{1}^{2}

… (i)

h (5 v_{0}) = h v_{0} + \frac{1}{2} m v_{2}^{2}

4 h v_{0} = \frac{1}{2} m v_{2}^{2}

… (ii) Divide (i) by (ii),

\frac{1}{4} = \frac{v _{1}^{2}}{v _{2}^{2}}

\frac{v _{1}}{v _{2}} = \frac{1}{2}

Q8PhysicsNEET UG PYQPhotons

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

E = h v

B. The velocity of a photon is c. C. The momentum of a photon,

p = \frac{h v}{c}

D. In a photon-electron collision, both total energy and total momentum are conserved. E. Photon possesses positive charge. Choose the correct answer from the options given below:

AA, B, C and D only

BA, C and D only

CA, B, D and E only

DA and B only

Answer key (A) & worked solution

Correct answer: Option A

E: photons have no change

Which topics in Dual Nature of Radiation and Matter carry the most questions?

All 5 topics, by tagged PYQs, then practice questions. Counted from the bank. Updated 19 Oct 2026.

Topic	PYQs	Practice questions
Wave Nature of Matter	18	60
Photoelectric Effect	9	55
Photons	7	52
Einstein's Photoelectric Equation	5	52
Miscellaneous Examples	1	5

Why does Dual Nature of Radiation and Matter show "–" until you answer 3 questions?

Unknown is not zero. Until you answer at least 3 graded questions in Dual Nature of Radiation and Matter, ViJEEta shows – instead of a zero or a 50% default. Book exercises can raise chapter mastery up to 0.60, adaptive practice up to 0.75, and only a timed chapter test or mock can certify 0.80 and above.

How ViJEEta scores you

What happens when you test Dual Nature of Radiation and Matter?

Every chapter test is 25 questions. It starts at moderate difficulty and adapts after each saved answer. If you open a solution before answering, that attempt earns no credit, so your mastery stays honest.

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Dual Nature of Radiation and Matter: NEET PYQs and weightage

Dual Nature of Radiation and Matter: formula sheet for NEET

Einstein's photoelectric equation

Stopping potential

Photon energy

Threshold frequency

Threshold form of Einstein's equation

V0 vs frequency straight line

Wavelength from stopping potential

Photon momentum

de Broglie wavelength

Photons per second

Intensity rule

Electron volt

Planck's constant

How does NEET ask Dual Nature of Radiation and Matter?

Which topics in Dual Nature of Radiation and Matter carry the most questions?

Why does Dual Nature of Radiation and Matter show "–" until you answer 3 questions?

What happens when you test Dual Nature of Radiation and Matter?

Chapters either side of Dual Nature of Radiation and Matter by weight