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Nuclear Reactions, Fission and Fusion for JEE: 42 solved questions

Real JEE paper questions on nuclear reactions, fission and fusion, part of nuclei. Each opens with the options, the correct answer and a step-by-step solution. Papers run from 2003 to 2026. No sign-in needed to read them.

What this topic asks

• Energy released in fission and fusion — 26 questions
• Q-value, decay and conservation laws — 16 questions

All 42 questions with solutions

• A nucleus at rest disintegrates into two smaller nuclei with their masses in the ratio of 2:1. After disinteg… JEE Main 9th April 2nd Shift 2024
• Two nuclei of mass number 3 combine with another nucleus of mass number 4 to yield a nucleus of mass number 1… JEE Main 4th April 1st Shift 2026
• The energy released if hydrogen atoms are combined to form ⁴₂He is MeV. (Take binding energies per nucleon of… JEE Main 6th April 2nd Shift 2026
• Energy released when two deuterons (₁H²) fuse to form a helium nucleus (₂He⁴) is (Given: Binding energy per n… JEE Main 2nd April 2nd Shift 2025
• ²³⁸₉₂A→²³⁴₉₀B+⁴₂D+Q. In the given nuclear reaction, the approximate amount of energy released will be [Given,… JEE Main 13th April 1st Shift 2023
• Nucleus A is having mass number 220 and its binding energy per nucleon is 5.6 MeV. It splits in two fragments… JEE Main 24th June 1st Shift 2022
• The Q-value of a nuclear reaction and kinetic energy of the projectile particle, Kₚ are related as JEE Main 28th June 1st Shift 2022
• A nucleus of mass M emits γ-ray photon of frequency u. The loss of internal energy by the nucleus is [Take c… JEE Main 20th July 1st Shift 2021
• A nucleus with mass number 184 initially at rest emits an α-particle. If the Q value of the reaction is 5.5 M… JEE Main 22nd July 2nd Shift 2021
• You are given the Mass of ⁷₃Li=7.0160 u, Mass of ⁴₂He=4.0026 u and Mass of ¹₁H=1.0079 u. When 20 g of ⁷₃Li is… JEE Main 6th Sept 1st Shift 2020
• A nucleus of mass M+Δ m is at rest and decays into two daughter nuclei of equal mass /M2 each. Speed of light… JEE Main 2010
• If the binding energy per nucleon in ⁷₃Li and ⁴₂He nuclei are 5.60 MeV and 7.06 MeV respectively, then in the… JEE Main 2006
• The binding energy per nucleon of deuteron (²₁H) and helium nucleus (⁴₂He) is 1.1 MeV and 7 MeV respectively.… JEE Main 2004
• The disintegration energy Q for the nuclear fission of ²³⁵U→¹⁴⁰Ce+⁹⁴Zr+n is MeV. Given atomic masses of ²³⁵U:… JEE Main 4th April 2nd Shift 2024
• If three helium nuclei combine to form a carbon nucleus then the energy released in this reaction is ×10⁻² Me… JEE Main 5th April 1st Shift 2024
• A nucleus with mass number 242 and binding energy per nucleon as 7.6 MeV breaks into two fragment each with m… JEE Main 8th April 1st Shift 2023
• A common example of alpha decay is ²³⁸₉₂U→²³⁴₉₀Th+₂He⁴+Q. Given: ²³⁸₉₂U=238.05060 u, ²³⁴₉₀Th=234.04360 u, ⁴₂H… JEE Main 12th April 2nd Shift 2023
• Two lighter nuclei combine to form a comparatively heavier nucleus by the relation given below: ²₁X+²₁X=⁴₂Y.… JEE Main 26th July 2nd Shift 2022
• Match the List-I with List-II. List-I: A. ¹₀n+²³⁵₉₂U→¹⁴⁰₅₄Xe+⁹⁴₃₈Sr+2 ¹₀n B. 2H₂+O₂→2H₂O C. ²₁H+²₁H→³₂He+¹₀n… JEE Main 3rd April 1st Shift 2025
• Choose the correct nuclear process from the below options [p: proton, n: neutron, e⁻: electron, e⁺: positron,… JEE Main 28th Jan 1st Shift 2025
• Which of the following nuclear fragments corresponding to nuclear fission between neutron (¹₀n) and uranium i… JEE Main 4th April 1st Shift 2024
• In a hypothetical fission reaction, ₉₂X²³⁶→₅₆Y¹⁴¹+₃₆Z⁹²+3R. The identity of emitted particles (R) is JEE Main 8th April 2nd Shift 2024
• The energy released in the fusion of 2 kg of hydrogen deep in the sun is E_H and the energy released in the f… JEE Main 9th April 2nd Shift 2024
• The explosive in a Hydrogen bomb is a mixture of ₁H², ₁H³ and ₃Li⁶ in some condensed form. The chain reaction… JEE Main 29th Jan 1st Shift 2024
• In a nuclear fission reaction of an isotope of mass M. Three similar daughter nuclei of same mass are formed.… JEE Main 30th Jan 2nd Shift 2024
• In a reactor, 2 kg of ₉₂U²³⁵ fuel is fully used up in 30 days. The energy released per fission is 200 MeV. Gi… JEE Main 2nd Sept 1st Shift 2020
• Given the masses of various atomic particles mₚ=1.0072 u, mₙ=1.0087 u, mₑ=0.000548 u, mᵤ=0, m_d=2.0141 u, whe… JEE Main 6th Sept 2nd Shift 2020
• Consider the nuclear fission Ne²⁰→2He⁴+C¹². Given that the binding energy/nucleon of Ne²⁰, He⁴ and C¹² are, r… JEE Main 10th Jan 2nd Shift 2019
• Two deuterons undergo nuclear fusion to form a Helium nucleus. Energy released in this process is (given bind… JEE Main Online 2017
• Imagine that a reactor converts all given mass into energy and that it operates at a power level of 10⁹ watt.… JEE Main Online 2017
• Statement-I: A nucleus having energy E₁ decays by β⁻ emission to daughter nucleus having energy E₂, but the β… JEE Main 2011 (Re-scheduled)
• When ₃Li⁷ nuclei are bombarded by protons, and the resultant nuclei are ₄Be⁸, the emitted particles will be JEE Main 2006
• A nuclear transformation is denoted by X(n,α) ⁷₃Li. Which of the following is the nucleus of element X? JEE Main 2005
• In the nuclear fusion reaction, ²₁H+³₁H→⁴₂He+n given that the repulsive potential energy between the two nucl… JEE Main 2003
• The energy released when 7/(17.13) kg of ⁷₃Li is converted into ⁴₂He by proton bombardment is α×10³² eV. The… JEE Main 6th April 1st Shift 2026
• The average energy released per fission for the nucleus of ²³⁵₉₂U is 190 MeV. When all the atoms of 47 g pure… JEE Main 23rd Jan 2nd Shift 2026
• A star has 100% helium composition. It starts to convert three ⁴He into one ¹²C via triple alpha process as ⁴… JEE Main 9th April 1st Shift 2024
• In a nuclear fission process, a high mass nuclide (A=236) with binding energy 7.6 MeV/Nucleon dissociated int… JEE Main 27th Jan 2nd Shift 2024
• The energy released per fission of nucleus of ²⁴⁰X is 200 MeV. The energy released if all the atoms in 120 g… JEE Main 24th Jan 2nd Shift 2023
• Two radioactive substances A and B of mass numbers 200 and 212 respectively, shows spontaneous α-decay with s… JEE Main 8th April 2nd Shift 2026
• A radioactive material P first decays into Q and then Q decays to non-radioactive material R. Which of the fo… JEE Main 4th April 2nd Shift 2025
• A radioactive nucleus n₂ has 3 times the decay constant as compared to the decay constant of another radioact… JEE Main 23rd Jan 1st Shift 2025