CBSE 2023 · Region 3 · Set 1 · Q23 · 2 marks
Draw a graph showing the variation of binding energy per nucleon as a function of mass number A . The binding energy per nucleon for heavy nuclei ( $\displaystyle \mathrm{A}>170$ ) decreases with the increase in mass number. Explain.Using Bohr's postulates, obtain the expression for radius of $\displaystyle \mathrm{n}^{\text {th }}$ stable orbit in a hydrogen atom.
Draw a graph showing the variation of binding energy per nucleon as a function of mass number A . The binding energy per nucleon for heavy nuclei ( $\displaystyle \mathrm{A}>170$ ) decreases with the increase in mass number. Explain.
Using Bohr's postulates, obtain the expression for radius of $\displaystyle \mathrm{n}^{\text {th }}$ stable orbit in a hydrogen atom.
Marking-scheme solution
(a)
Graph of binding energy per nucleon as a function of mass number A Explanation
Mass number ( \(\displaystyle \mathrm{A}\) )
Explanation:-Nuclear forces are short range & show saturation, while the electrostatic force are neither short range nor show any saturation. Hence for heavier nuclei \(\displaystyle (\mathrm{A}>170)\) the electrostatic force of repulsion becomes predominant, decreasing the binding energy per nucleon.
Alternatively:-As the size of the nucleus increases, the nucleus becomes unstable.
NucleiMass-Energy and Nuclear Binding EnergyApplyvery_short_answermedium
More from Nuclei
- Explain the terms mass defect and binding energy. How are they related?2026 · asked 3×
- (i) Prove that the nuclear density is same for all nuclei. (ii) Draw a plot of potential energy of a pair of…2023 · asked 3×
- Differentiate between nuclear fission and nuclear fusion. Give one example for each with nuclear reaction.2026 · asked 3×
- Assertion: The binding energy per nucleon is practically constant for mass number in the range ( 30<A<170 ).…2025 · asked 3×
- (i) Write any two features of nuclear forces. (ii) If both the number of protons and the neutrons are…2026 · asked 3×
- Assertion: During formation of a nucleus, the mass defect produced is the source of the binding energy of the…2025 · asked 3×
- Which of the following statements is not true for nuclear forces?2023 · asked 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…2022 · asked 3×
CBSE Class 12 Physics past-paper question from the 2023board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.