Nuclei

CBSE Class 12 Physics · every board question from this chapter, 2022–2026 · 36 of them repeated across years

• The distance-of-closest-approach for an alpha particle is 'd' when it moves head-on with speed v towards a target nucleus. If the…2026
• Nuclides with the same number of neutrons are called:2026
• The radius of a nucleus of mass number 125 is2026asked 3×
• Consider the nuclear reaction X → Y+Z. Let M x, M y and M z be the masses of the three nuclei X, Y and Z respectively. Then which…2026
• If r 1 and r 2 are the radii of atomic nuclei of mass numbers 64 and 27 respectively, then the value of ((r 1)/(r 2)) is:2026asked 2×
• Reason: The mass of a nucleus is less than the sum of the masses of the constituent nucleons. Reason (R): Energy is absorbed when…2026asked 3×
• Assertion: Energy is released when heavy nuclei undergo fission or light nuclei undergo fusion. Reason (R): For heavy nuclei,…2026asked 3×
• Assertion: Nuclear forces are always attractive. Reason (R): The nuclear force between protons and neutrons in a nucleus is a…2026asked 3×
• Explain the terms mass defect and binding energy. How are they related?2026asked 3×
• Prove that the density of nuclear matter is same for all nuclei.2026
• Suppose a nucleus with mass number A=240 and (B. E.)/ =7.6 MeV, breaks into two nuclei, each of mass number A=120 with (B. E.)/…2026
• Draw a graph showing variation of binding energy per nucleon as a function of mass number A. The binding energy per nucleon for…2026
• Draw the plot of potential energy of a pair of nucleons as a function of their separation. Write two important conclusions that…2026
• Consider the following nuclides: 6^12 C, 80^198 Hg, 6^14 C, 79^197 Au Group them into isotopes and isotones. How does the size of…2026asked 3×
• (i) Write any two features of nuclear forces. (ii) If both the number of protons and the neutrons are conserved in each nuclear…2026asked 3×
• Distinguish between isotopes and isobars, giving one example for each. Derive the relation between atomic mass unit (u) and…2026
• Differentiate between nuclear fission and nuclear fusion. Give one example for each with nuclear reaction.2026asked 3×
• In the nuclear reaction: 1^2 H+ 1^2 H → 2^A X+ 0^1 n Find the value of A. Calculate the amount of energy released in the…2026
• Draw a plot showing the variation of potential energy of a pair of nucleons as a function of their separation (r). Using this…2026
• A deuterium nucleus and an alpha particle approach a target nucleus separately in head-on position. Find the ratio of their…2026
• The mass numbers of two nuclei A and B are 27 and 64 respectively. The ratio of their radii ((r A)/(r B)) will be:2025
• Which of the following figures correctly represent the shape of curve of binding energy per nucleon as a function of mass number?2025asked 3×
• Isotones are the nuclides having:2025asked 3×
• Inside a nucleus, the nuclear forces between proton and proton, proton and neutron, neutron and neutron are F pp, F pn and F nn…2025asked 3×
• Assertion: During formation of a nucleus, the mass defect produced is the source of the binding energy of the nucleus. Reason ( R…2025asked 3×
• Assertion: The binding energy per nucleon is practically constant for mass number in the range ( 30<A<170 ). Reason (R): Nuclear…2025asked 3×
• Define the term, 'distance of closest approach'. A proton of 3.95 MeV energy approaches a target nucleus Z=79 in head-on…2025
• Why is the mass of a nucleus always less than the sum of the masses of its constituents, i.e. free neutrons and free protons? How…2025
• An alpha particle and a deuterium ion are accelerated through the same potential difference. These are then directed towards a…2025
• Calculate the mass of an α -particle in atomic mass unit ( u ). Given, Mass of a normal helium atom =4 · 002603 u Mass of carbon…2025
• When a neutron collides with 92^235 U, the nucleus gives 54^140 Xe and 38^94 Sr as fission products and two neutrons are ejected.…2025
• Briefly explain how energy is produced in stars, giving two examples of the nuclear reactions involved.2025
• Calculate the binding energy per nucleon (in MeV ) of a helium nucleus ( 2^4 He ). Given: m( 2^4 He)=4 · 002603 u2025
• Differentiate between 'nuclear fission' and 'nuclear fusion'. Briefly discuss one example of each. Draw a graph of potential…2025
• Show the variation of binding energy per nucleon with mass number. Write the significance of the binding energy curve. Two nuclei…2025asked 3×
• Define'Mass defect'and'Binding energy'of a nucleus. Describe 'Fission process'on the basis of binding energy per nucleon. A…2025asked 3×
• Consider the so-called'D-T reaction' (Deuterium-Tritium reaction). In a thermonuclear fusion reactor, the following nuclear…2025
• The potential energy between two nucleons inside a nucleus is minimum at a distance of about2024asked 3×
• Deuterium undergoes the following fusion reaction: 1^2 H+ 1^2 H → 2^3 He+ 0^1 n+3.27 MeV How long an electric bulb of 200 W will…2024
• Calculate the energy released/absorbed in the following nuclear reaction: 6^12 C+ 6^12 C → 10^20 Ne+ 2^4 He Given: m( 6^12 C)=12…2024asked 2×
• The carbon isotope 6^12C has a nuclear mass of 12.000000 u. Calculate the binding energy of its nucleus. Given m p = 1.007825 u;…2024
• Calculate the energy released/absorbed (in MeV ) in the nuclear reaction:2024
• Differentiate between nuclear fission and fusion. The fission properties of 94 Pu^239 are very similar to those of 92 U^235. How…2024asked 3×
• Briefly discuss three characteristics of the forces between nucleons. Which out of 4^8 X and 3^5 Y nuclei is more stable and why?2024
• Plot a graph depicting potential energy of a pair of nucleons in a nucleus as a function of their separation. Identify the…2024
• Define atomic mass unit (u). Calculate the energy required to separate a deuteron into its constituent parts (a proton and a…2024asked 3×
• Write two characteristic properties of nuclear force. Draw a plot of potential energy of a pair of nucleons as a function of…2024
• State any two properties of a nucleus. Why is the density of a nucleus much more than that of an atom? Show that the density of…2024asked 2×
• The atomic number of an atom represents:2023
• The radius of 13^27 X nucleus is R. The radius of 53^125 Y nucleus will be2023
• Two nuclei have their mass numbers in the ratio of 8: 1. The ratio of their nuclear densities is:2023
• Which of the following statements is not true for nuclear forces?2023asked 3×
• The ratio of the nuclear densities of two nuclei having mass numbers 64 and 125 is2023asked 3×
• The difference in mass of ^7 X nucleus and total mass of its constituent nucleons is 21.00 u. The binding energy per nucleon for…2023asked 3×
• The mass density of a nucleus of mass number A is:2023
• The curve of binding energy per nucleon as a function of atomic mass number has a sharp peak for helium nucleus. This implies…2023asked 3×
• Assertion: The nucleus 3^7 X is more stable than the nucleus 3^4 Y. Reason (R): 3^7 X contains more number of protons.2023asked 3×
• Draw a graph showing the variation of potential energy of a pair of nucleons as a function of their separation. Indicate the…2023
• Draw a graph showing the variation of potential energy of a pair of nucleons as a function of their separation. Indicate the…2023
• Briefly describe the multi-step process involved in the generation of energy in the Sun.2023
• Show that the density of a nucleus is independent of its mass number. Why are lighter nuclei more stable than heavier nuclei?2023
• Draw a graph showing the variation of binding energy per nucleon as a function of mass number A. The binding energy per nucleon…2023asked 3×
• Draw the graph showing the variation of binding energy per nucleon with mass number A of nuclei (2<A<170). Use this graph to…2023
• Draw a plot showing the variation of potential energy of two nucleons as a function of distance between them. Identify the…2023
• (i) Prove that the nuclear density is same for all nuclei. (ii) Draw a plot of potential energy of a pair of nucleons as a…2023asked 3×
• Calculate the binding energy of an alpha particle in MeV. Given mass of a proton =1.007825 u mass of a neutron =1.008665 u mass…2023
• (i) Distinguish between nuclear fission and fusion giving an example of each. (ii) Explain the release of energy in nuclear…2023asked 3×
• (i) Distinguish between isotopes and isobars. (ii) Two nuclei have different mass numbers A 1 and A 2. Are these nuclei…2022asked 3×
• Differentiate between nuclear fission and nuclear fusion. Deuterium undergoes fusion as per the reaction: 1^2 H+ 1^2 H → 2^3 He+…2022asked 3×
• Calculate the energy released in MeV in the following reaction: 1^2 H+ 1^3 H → 2^4 He+n Given: m( 1^2 H)=2.014102 u2022asked 3×
• In Geiger-Marsden experiment, calculate the distance of closest approach for an alpha particle with energy 2.56 × 10^-12 J.…2022asked 3×
• In a fission event of 92^238 U by fast moving neutrons, no neutrons are emitted and final products, after the beta decay of the…2022asked 3×
• A narrow beam of protons, each having 4.1 MeV energy is approaching a sheet of lead (Z=82). Calculate: (i) the speed of a proton…2022asked 2×
• Depict the variation of the potential energy of a pair of nucleons with the separation between them. Imagine the fission of a…2022asked 3×
• James Chadwick, in 1932, studied the emission of neutral radiations when Beryllium nuclei were bombarded with alpha particles. He…2022

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