Q.1. Samples of two radioactive nuclides A and B are taken λA and λB are the disintegration constants of A and B respectively. In which of the following cases, the two samples can simultaneously have the same decay rate at any time?
Q 2. Radioactivity is the phenomenon associated with
Q 3. Which of the following are not emitted by radioactive substances?
Q.5. For a nuclear fusion process, suitable nuclei are
Q.6. In the uranium radioactive series, the initial nucleus is 92U238 and that the final nucleus is 82Pb206. When uranium nucleus decays to lead, the number of α particles and β particles emitted are
Q.7. The nuclear radius is of the order of
Q.8. Particles which can be added to the nucleus of an atom without changing its chemical properties are called
Q.9. The radius of a nucleus is
Q.10. Nucleus of an atom whose atomic mass is 24 consists of
Q.11. The electrons cannot exist inside the nucleus because
Q.12. In …X… water is circulated though the reactor vessel and transfers energy to steam generator in the …Y… Here, X and Y refer to
Q.13. A nuclei having same number of neutron but different number of protons / atomic number are called
Q.14. Which one of the following has the identical property for isotopes?
Q.15. The number of protons in an atom of atomic number Z and mass number A is
Q.16. When the number of nucleons in nuclei increases, the binding energy per nucleon
Q.17. Mp denotes the mass of a proton and Mn that of a neutron. A given nucleus, of binding energy B, contains Z protons and N neutrons. The mass M(N, Z) of the nucleus is given by (c is the velocity of light)
Q.18. Mass energy equation was propounded by
Q.19. The mass of an atomic nucleus is less than the sum of the masses of its constituents. This mass defect is converted into
Q.20. Which of the following statement is not true regarding Einsteins mass energy relation?
Q.21. The curve of binding energy per nucleon as a function of atomic mass number has a sharp peak for helium nucleus. This implies that helium
Q.22. Nuclear forces are
Q.23. Nuclear forces exists between
Q.24. The antiparticle of electron is
Q.25. Neutron decay in free space is given as follows 0n1 → 1H1 + -1e0 +  Then the parenthesis [ ] represents a
Q.26. Radioactivity is
Q.27. γ-rays are deflected by
Q.28. Beta rays emitted by a radioactive material are
Q.29. Which of the following is not a mode of radioactive decay ?
Q.30. The half-life period and the mean life period of a radioactive element are denoted respectively by Th and Tm. Then
Q.31. In γ ray emission from a nucleus
Q.32. Artificial radioactivity was discovered by
Q.33. Radioactive samples are stored in lead boxes because it is
Q.34. The process of radioactive radiations remains unaffected due to
Q.35. A radioactive material undergoes decay by ejecting electrons. The electron ejected in this process is
Q.36. The same radioactive nucleus may emit
Q.37. Which of the following of a radioactive material is a measure of its instability?
Q.38. The rate of disintegration at a given instant, is directly proportional to the number of Nuclei present at that instant. This is the statement of
Q.39. Three specimens A, B, C of same radioactive element has activities 1 microcurie, 1 rutherford and 1 becquerel respectively. Which specimen has maximum mass?
Q.40. If a radioactive element is placed in an evacuated chamber, then the rate of radioactive decay will
Q 41. Tritium is an isotope of hydrogen whose nucleus Triton contains 2 neutrons and 1 proton. Free neutrons decay into p + e¯+v¯. If one of the neutrons in Triton decays, it would transform into He3 nucleus. This does not happen. This is because [NCERT Exemplar]
Q.42. Radioactive substance emits
Q43. When a β-particle is emitted from a nucleus then its neutron-proton ratio
Q44.. A radioactive nucleus emits a beta particle. The parent and daughter nuclei are
Q45. The quantity which is not conserved in a nuclear reaction is
Q.46. The ‘rad’ is the correct unit used to report the measurement of
Q.47. One curie is equal to
Q.48. Half life of radioactive element depends upon
Q.49. A nuclear reaction is given by ZXA → Z+1YA + -1e0 + ν̅
Q.50. Fusion reaction occurs at temperatures of the order of