JEE Main Atoms, Nuclei and Dual Nature of Radiation questions with solutions
Bohr model, hydrogen spectrum, photoelectric effect, matter waves, X-rays, radioactivity and nuclear binding energy. 29 questions from our 2016–2025 JEE Main pattern papers, from the Class 12 Physics syllabus. Each has the answer and a full solution.
Also practise: Atoms, Nuclei and Dual Nature of Radiation for JEE Advanced
JEE Main 2025
JEE Main 2024
JEE Main 2023
- Light of wavelength 200 nm falls on a metal of work function 2.2 eV. Using hc=1240 eV nm, the de Broglie wavelength of the fastest photoelectrons is…
- A radioactive nucleus can decay by two independent modes: by α-emission with partial half-life 6 h and by β-emission with partial half-life 3 h.…
- The electron in a doubly ionised lithium ion (Li^2+) drops from the n=3 level to n=2. The emitted photon falls on a stationary hydrogen atom in its…
- In a hypothetical fusion reactor, two deuterium nuclei fuse to form a helium-4 nucleus. Take the binding energy per nucleon as 1.0 MeV for deuterium…
JEE Main 2022
- Light of wavelength 300 nm incident on a metal surface gives photoelectrons with maximum kinetic energy K1. When wavelength 200 nm is used, the…
- Two radioactive samples contain equal numbers of nuclei at t=0. Sample P has half-life 10 min and sample Q has half-life 20 min. After how many…
- A hydrogen-like ion emits a photon of energy 108.8 eV when its electron makes a transition from n=3 to n=1. Taking the hydrogen ground-state energy…
JEE Main 2021
- A hydrogen atom makes a transition from n=3 to n=1 and the emitted photon falls on a metal surface of work function 4.5 eV. Taking En=-13.6/n^2 eV…
- Radioactive samples A and B initially contain equal numbers of nuclei. The half-life of A is 2 h and that of B is 6 h. The ratio of the activity of A…
- Light of wavelength 200 nm falling on a metal produces photoelectrons whose maximum kinetic energy is three times that obtained with light of…
JEE Main 2020
- A Li^2+ ion emits a photon of the same wavelength as the first line of the Lyman series of hydrogen (n=2→ n=1). The transition in Li^2+ responsible is
- Two radioactive samples A and B contain equal numbers of atoms at t = 0. Their half-lives are 1 h and 2 h respectively. The activities of the two…
- In a photoelectric experiment the stopping potential is 2.0 V for light of wavelength 310 nm and 3.0 V for light of wavelength 248 nm. Without using…
JEE Main 2019
- When light of wavelength 400 nm falls on a metal surface, the stopping potential is 1.0 V. If the surface is illuminated with light of wavelength 300…
- A Li^2+ ion has a single electron. The wavelength of the photon emitted when this electron makes a transition from the third orbit to the second…
- In the reaction ^21H+^21H→^32He+^10n, the atomic masses are 2.0141 u for deuterium, 3.0160 u for helium-3 and 1.0087 u for the neutron (1 u=931.5…
JEE Main 2018
- A laser delivers a parallel beam of power 15 W and falls on a perfectly reflecting plane mirror at an angle of incidence of 60^° (measured from the…
- A singly ionised helium ion He^+ makes a transition from the n=4 level to the n=2 level. Using the Bohr model with En=-13.6 Z^2/n^2 eV and hc=1240 eV…
- Two radioactive samples A and B contain equal numbers of nuclei at t=0. Their half-lives are 20 minutes and 40 minutes respectively. The activities…
JEE Main 2017
- The Kα X-ray line of copper (Z = 29) has wavelength 154 pm. Assuming Moseley's law, √(nu) propto (Z - 1), the wavelength of the Kα line of iron (Z =…
- A beam of electrons, each of energy 12.5 eV, is passed through hydrogen gas in its ground state, and the atoms excited by collisions are allowed to…
- Two radioactive samples A and B have half-lives of 10 minutes and 20 minutes and contain the same number of nuclei at t = 0. At t = 40 minutes the…
JEE Main 2016
- For a certain metal the stopping potential is 2 V for light of frequency nu and 6 V for light of frequency 2nu. Taking hc=12400 eV AA, the threshold…
- The photon emitted when the electron of a doubly ionised lithium ion Li^2+ jumps from the n=3 to the n=2 level falls on a metal of work function 4…
- Two radioactive samples A and B contain the same number of nuclei initially. The half-life of A is 2 h and that of B is 4 h. After 8 h the ratio of…
Other Physics topics
Calorimetry and Heat Transfer 13Capacitors 10Current Electricity 13Electromagnetic Induction and Alternating Current 16Electrostatics 15Fluid Mechanics, Elasticity and Surface Tension 15Gravitation 10Kinematics and Laws of Motion 27Magnetic Effects of Current 24Ray and Wave Optics 16Rotational Motion 16Semiconductors and Communication 11Simple Harmonic Motion 11Thermodynamics and Kinetic Theory of Gases 19Units and Measurements 10Waves and Sound 23Work, Energy and Power 11