Modern Physics in JEE Main 2026: Latest Practice Questions with Stepwise Solutions

Modern Physics in JEE Main 2026 is the study of phenomena that cannot be explained by classical physics. The subject includes photoelectric effect, Bohr’s model of the atom, nuclear physics, X-rays, and the wave-particle duality of matter and radiation. You can master the Modern Physics part by solving sample questions, previous years' questions and the questions given here with solutions. We have combined the different topics and provided questions with step-wise solutions here. If you want to get a good score in the exam, you need to read this article and find the JEE Main Modern Physics latest questions with solutions.

Also Check - JEE Main 2026 Ray and Wave Optics Practice Sets with Solved Examples

Practice Questions for JEE Main 2026 Modern Physics

Find some of the JEE Main Modern Physics questions with solutions here.

Q1. An electron is accelerated through a potential difference of 100 V. What is its de Broglie wavelength? (Mass of electron = 9.11×10⁻³¹ kg, h = 6.63×10⁻³⁴ J·s, 1 eV = 1.6×10⁻¹⁹ J)

Solution

Electron accelerated through V = 100 V → kinetic energy ≈ 100 eV = 100×1.6×10⁻¹⁹ J = 1.60×10⁻¹⁷ J.

Momentum p = \sqrt{2mE} = \sqrt{2×9.11×10^{-31}×1.60×10^{-17}} ≈ \sqrt{2.915×10^{-47}} ≈1.707×10^{-23}

Thus λ = h/p = 6.63×10−34/ 1.707×10−23 ≈ 3.88×10−11m ≈ 0.0388nm = 0.12 nm

Answer: 0.12 nm

Q2. According to the Bohr model for the hydrogen atom, the frequency of radiation emitted when the electron falls from n = 4 to n = 2 is:

Solution

For hydrogen: En=−13.6 eV/n2E_n = -13.6\,\text{eV}/n^2En​=−13.6eV/n2.

For n = 4: E₄ = –13.6/16 = –0.85 eV. For n = 2: E₂ = –13.6/4 = –3.40 eV.

Energy difference ΔE = E₂ – E₄ = (–3.40) – (–0.85) = –2.55 eV → photon energy = 2.55 eV. In joule: 2.55×1.6×10⁻¹⁹ J ≈4.08×10⁻¹⁹ J. Frequency ν = E/h = 4.08×10⁻¹⁹ /6.63×10⁻³⁴ ≈6.15×10¹⁴ Hz = 6.2×10¹⁴ Hz

Answer: 6.2×10¹⁴ Hz

Also Check - Atoms and Nuclei JEE Main Questions 2026: Important Practice Questions with PYQs

Download JEE Main Modern Physics Sample Questions with Solutions PDF

You can find out the JEE Main Modern Physics exam questions with solutions in the PDF format below:

JEE Main 2026 Modern Physics Key Topics and Weightage

The  JEE Main 2026 Modern Physics syllabus and weightage can be checked from the table below:

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Quick Preparation Tips for JEE Main 2026 Modern Physics

Find here some of the quick tips for JEE Main 2026 Modern Physics:

• Know the Modern Physics syllabus, such as Photoelectric Effect & Photons, Atoms & Bohr’s Model, X-rays & Moseley’s Law, Radioactivity (α, β, γ decay) etc.

• You must now know radius, energy levels, spectral lines, n-type/p-type, diode behaviour, forward/reverse bias etc.

• Read books such as NCERT Physics Class 12, H.C. Verma Vol 2, D.C. Pandey / Arihant Physics for JEE etc.

With the right strategy and preparation, one can score easy 15-18 marks in Modern Physics. To identify the changing trends, review the latest sample questions and follow the worked out solutions so you don't skip any crucial step. We hope this article will help you to prepare for the JEE Main 2026 exam smoothly with the help of the latest exam questions and solutions.

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