Title 13. NUCLEI(H).pdf ✅

NEET REVISION 13. NUCLEI(H) NEET REVISION Date: March 18, 2025 Dura on: 1:00:00 Total Marks: 180 INSTRUCTIONS INSTRUCTIONS PHYSICS 1. The count rate of a radioactive sample falls from disintegration/s to disintegration/s in 20 hours. The count rate after 100 hours from beginning is found to be disintegration/s. Find the value of is [Q364016] (1) 3.91 (2) 5.65 (3) 1.7 (4) 7.25 2. In the reaction if the binding energies of and are respec‐ tively and (in ) then the energy (in ) released is [Q363658] (1) (2) (3) (4) 3. The binding energy of deutron is per nucleon and an -particle has a binding energy of per nucleon. Then in the fusion reaction the energy released is [Q363695] (1) (2) (3) (4) 4. In a fission reaction the average binding energy per nucleon of and is whereas that of is . The total energy liberated will be about : [Q363719] (1) (2) (3) (4) 5. A star initially has deuterons. It produces energy via the processes The masses of the nuclei are as follows: If the average power radiated by the star is the deuteron supply of the star is ex‐ hausted in a time of the order of [Q363751] (1) (2) (3) (4) 6. In a reactor, of fuel is fully used up in 30 days. The energy released per fission is . Given that the Avogadro number, per kilo mole and . The power output of the reactor is close to [Q363781] (1) (2) (3) (4) 7. The ratio of the amounts of energy released as a result of the fusion of hydrogen and fission of of will be (Given en‐ ergy released fusion of Hydrogen is and that released per fission of is ) [Q363773] (1) 4.13 (2) 3.28 (3) 5.28 (4) 1.28 8. Sun radiates energy in all directions. The average energy received at earth is . The av‐ erage distance between the earth and the sun is . If this energy is released by con‐ servation of mass into energy, then the mass lost per day by the sun is approximately (Use 1 day ) [Q363704] (1) (2) (3) (4) 9. The half-life of a radioactive substance is days. What is the probability of the decay of a nucleus in 1 year? [Take ] [Q363989] 4.0 × 10 6 1.0 × 10 6 N × 10 3 N 2 1H + 3 1 H →4 2 He +1 0 n, 2 1H , 3 1H 4 2He a, b c MeV MeV a + b − c a + b + c c + a − b c − a − b 2 1H 1.112 MeV α 4 2He 7.047 MeV 2 1H +2 1 H →4 2 He + Q, Q 11.9 MeV 1 MeV 931 MeV 23.8 MeV 236 92 U→117X+117Y + n + n, X Y 8.5 MeV 236U 7.6 MeV 236 92 U → 117X + 117Y + n + n 200 keV 2 MeV 200 MeV 2000 MeV 10 40 1H2+1H2→1H3 + p 1H2+1H3→2He 4 + n M(H2) = 2.014 amu; M(p) = 1.007 amu; M(n) = 1.008 amu; M(He 4) = 4.001 amu 10 16W, 10 8 sec 10 6 sec 10 16 sec 10 12 sec 2 kg 92U 235 200 MeV N = 6.023 × 10 26 1 eV = 1.6 × 10 −19J 125 MW 60 MW 35 MW 54 MW 1 kg (E1) 1 kg 92U 236 (E2) 28 MeV U 236 200 MeV 1.4 kW/m2 1.5 × 10 11 m = 86400 sec 4.4 × 10 9 kg 7.6 × 10 14 kg 3.8 × 10 12 kg 3.8 × 10 14 kg τ = 20 e −0.038 = 0.963, ln 2 = 0.693
NEET REVISION (1) (2) (3) (4) 10. fissions per second are taking place in a nuclear reactor having efficiency . The en‐ ergy released per fission is . The power output of the reactor is [Q363717] (1) (2) (3) (4) 11. The natural logarithm of the activity of a ra‐ dioactive sample varies with time as shown. At , there are undecayed nuclei. Then is equal to [Take ] [Q363998] (1) 7,500 (2) 3,500 (3) 75,000 (4) 12. If of a radioactive substance decay in 10 days. The amount of the original material left af‐ ter 30 days is [Q363969] (1) (2) (3) (4) 13. In a nuclear reactor using , the power out‐ put is . If energy released per fission of is , then the number of fissions per second is ( ) [Q363779] (1) (2) (3) (4) 14. The half life of a radioactive substance is . The time taken, for disintegrating th part of its original mass will be [Q364015] (1) (2) (3) (4) 15. A nucleus of has a half-life of 24.1 days. How long a sample of take to change to of it to ? [Q364039] (1) (2) (3) (4) 16. In the fusion reaction, the masses of deuteron, helium and neutron expressed in amu are 2.015, 3.017 and 1.009, respectively. If of deu‐ terium undergoes complete fusion, then find the amount of total energy released. [Q363767] (1) (2) (3) (4) 17. An atomic power nuclear reactor can deliver . The energy released due to fission of each nucleus of uranium atoms fissioned per hour will be [Q363736] (1) (2) (3) (4) 18. A radioactive nucleus (initial mass number and atomic number ) emits particles and 2 positrons. the ratio of number of neutrons to that of protons in the final nucleus will be [Q363927] (1) (2) (3) (4) 19. The radioactivity of a given sample of scotch due to tritium (half-life 12 years) was found to be only 3% of that measured in a recently pur‐ chased bottle marked “7 years old”. The sample must have been prepared about [Q363967] (1) 67 years back (2) 220 years back (3) 300 years back (4) 400 years back 20. Substance has atomic mass number 16 and half life of 1 day. Another substance has atomic mass number 32 and half life of day. If both and simultaneously start undergo ra‐ dioactivity at the same time with initial mass each, how many total atoms of and combined would be left after 2 days. [Q363984] (1) (2) (3) (4) 21. A nucleus of mass at rest emits an - particle. Kinetic energy of the - particle is . The recoil energy of the daughter nu‐ cleus is [Q363907] (1) (2) (3) (4) 22. A radioactive isotope has a half-life of . How long will it take the activity to reduce to of its original value? [Q363976] (1) (2) (3) (4) 23. The energy released in the fusion of of hy‐ drogen deep in the sun is and the energy re‐ leased in the fission of of is . The ratio is approximately (Consider the fusion reaction as, en‐ ergy released in the fission reaction of is 2.5 % 3.7 % 5.6 % 1.8 % 10 14 40% 250 MeV 2000 W 4000 W 1600 W 3200 W R t t = 0 N0 N0 e 2 = 7.5 1, 50, 000 20% 51.2% 62.6% 15% 21.2% U 235 9.6 MW U 235 200 MeV 1 eV = 1.6 × 10 −19J 3 × 10 11 3 × 10 17 3 × 10 23 3 × 10 18 T 7 8 T 8T 3T 2T Ux1 Ux1 90% Ux2 30 d 50 d 90 d 80 d 1 kg (1 amu = 931.5 MeV ) 9 × 10 13 J 20 × 10 5 J 4 × 10 22 5 × 10 15 300 MW 30 × 10 25 10 × 10 25 4 × 10 22 5 × 10 15 A Z 3α− A−Z−8 Z−4 A−Z−4 Z−8 A−Z−12 Z−4 A−Z−4 Z−2 A B 1/2 A B 320 g A B 3.38 × 10 24 6.76 × 10 24 1.69 × 10 24 6.76 × 10 23 214 amu α α 6.7 MeV 1.0 MeV 0.5 MeV 0.25 MeV 0.125 MeV T yr 1% 3.2 Tyr 4.6 Tyr 6.6 Tyr 9.2 Tyr 2 kg EH 2 kg 235U EU EH EU 4 1 1H + 2e − →4 2 He + 2v + 6γ + 26.7MeV 235U
NEET REVISION per fission nucleus and [Q363740] (1) 15.04 (2) 25.6 (3) 7.62 (4) 9.13 24. The mass of proton, neutron and helium nu‐ cleus are respectively and The binding energy of helium nucleus is [Q363679] (1) (2) (3) (4) 25. The fossil bone has a ratio, which is of that in a living animal bone. If the half- life time of is 5730 years then the age of the fossil bone is [Q363879] (1) 11460 years (2) 17190 years (3) 22920 years (4) 45840 years 26. A bone fragment found in a cave contains 0.21 times as much as an equal amount of carbon in air when the organism containing bone died. Find the approximate age of fragment of years. [Q363876] (1) (2) (3) (4) 27. The binding energy of two nuclei and are joule and joule respectively. If then the energy change in the reaction will be [Q363687] (1) (2) (3) (4) 28. The binding energies per nucleon for a deutron and an -particle are and respectively. What will be the energy released in the fol‐ lowing reaction? [Q363651] (1) (2) (3) (4) 29. Intensity of gamma rays falls to one eighth of its value after passing through of lead. What should be the thickness of the lead sheet to reduce the intensity to half? [Q363945] (1) (2) (3) (4) 30. Carbon 14 decays with half-life of about 5,800 years. In a sample of bone, the ratio of carbon 14 to carbon 12 is found to be of what it is in free air. This bone may belong to a period about centuries ago, where is nearest to [Q363878] (1) (2) (3) (4) 31. In the given reaction Radioactive radiations are emitted in the se‐ quence [Q363899] (1) (2) (3) (4) 32. A small quantity of solution containing radio nuclide of activity 1 microcurie is injected into the blood of a person. A sample of the blood of volume taken after 5 hours shows an ac‐ tivity of 296 disintegration per minute. What will be the total volume of the blood in the body of the person? Assume that the radioactive solution mixes uniformly in the blood of the person (Take 1 Curie disintegration per second and where disintegration constant) [Q363979] (1) 2 litres (2) 5.94 litres (3) 1 litres (4) 317 litres 33. Ba-122 has half-life of 2 min . Experiment has to be done using Ba-122 and it takes 10 min to set up the experiment. If initially of was taken, how much Ba was left when experiment was started? [Q364024] (1) (2) (3) (4) 34. A human body excretes certain material by a law similar to radioactivity. The body excretes half the amount injected in . Find the time in which activity falls to . If a person is in‐ jected technitium and its activity just after the injection is [Q364045] (1) (2) (3) (4) 35. Assuming that about of energy is re‐ leased per fission of nuclei, then the mass of consumed per day in a fission reactor of power 1 megawatt will be approximately: [Q363730] (1) (2) (3) (4) 36. A nucleus undergoes following transforma‐ tion then [Q363940] 200 MeV NA = 6.023 × 10 23 ) 1.0073 u, 1.0087 u 4.0015 u. 14.2 MeV 56.8 MeV 7.1 MeV 28.4 MeV 14C: 12C ( ) 1 16 14C 14 6 C t1/2 14C = 5730 1.3 × 10 4 y 1.15 × 10 4 y 1.4 × 10 4 y 1.24 × 10 4 y p n Q2n x y 2x > y, p n + p n = Q2n 2x − y 2x + y x + y xy α x1 x2 Q 1H 2 + 1H 2 → 2He 4 + Q 4 (x2 − x1) 4 (x1 + x2) 2 (x2 − x1) 2 (x1 + x2) 18 mm 2 mm 6 mm 9 mm 12 mm 1 4 x x 58 2 × 58 3 × 58 58/2 ZXA → Z+1Y A → Z−1KA−4 → Z−1KA−4 β, α, γ α, β, γ β, γ, α γ, α, β Na 24 1cm3 = 3.7 × 10 10 e −λt = 0.7927; λ = 80g Ba − 122 2.5 g 5 g 10 g 20 g 24h 3μCi (t1/2 = 6h) 6μCi. 6 h 4.8 h 6.3 h None ofthese 200 MeV 92U 235 U 235 10, 000 g 10 −2 g 1 g 100 g X X −−→ Y −2α Y −−−→ Z −4β −