Nuclei PYQs Set 8 (PDF)

Set 8 of 8 · Questions 211-237 of 237

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Mere Teacher · Previous Year Questions NEET Physics · Nuclei · Set 8 (Q211-237)
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211. $Solar energy is mainly caused due to$ (1) $burning of hydrogen in the oxygen$ (2) $fission of uranium present in the Sun$ (3) $fusion of protons during synthesis of heavier elements$ (4) $gravitational contraction$ 212. $At time t = 0, a material is composed of two radioactive atoms A and B, where N_{A} (0) = 2 N_{B} (0) . The decay constant of both kind of radioactive atoms is λ . However, A disintegrates to B and B disintegrates to C. Which of the following figures represents the evolution of N_{B} (t) / N_{B} (0) with respect to time t? (& N_{A} (0) = No . of A atoms at t = 0 & N_{B} (0) = No . of B atoms at t = 0)$ (1) (2) (3) (4) 213. $During a β decay$ (1) $a neutron in the nucleus decays emitting an electron$ (2) $a proton in the nucleus decays emitting an electron$ (3) $an atomic electron is ejected$ (4) $an electron which is already present within the nucleus is ejected.$ 214. $The mass of α ‐particle is$ (1) $less than the sum of masses of two protons and two neutrons$ (2) $equal to mass of four protons$ (3) $equal to mass of four neutrons$ (4) $equal to sum of masses of two protons and two neutrons$ 215. $If the nuclear force between two protons, two neutrons and between proton and neutron is denoted by F_{pp}, F_{nn} and F_{pn} respectively, then$ (1) $Fpp>Fnn=Fpn$ (2) $F_{pp} \neq = F_{nn} and F_{pp} = F_{nn}$ (3) $F_{pp} = F_{nn} = F_{pn}$ (4) $F_{pp} \neq = F_{nn} \neq = F_{pn}$ 216. $The ratio of mass densities of nuclei of^{40} Ca and^{16} O is close to:$ (1) $1$ (2) $0.1$ (3) $5$ (4) $2$ 217. $The half life of a radioactive nuclide is$ (1) $Half the time needed for a sample to complete decay.$ (2) $Half the time a sample can be kept before it starts to decay.$ (3) $The time needed for half a sample to decay.$ (4) $The time needed for the rest of a sample to decay one half of it has already decayed.$ 218. $Which one of the following pairs of nuclei are isotones?.$ (1) $_{34}^{74} Se,_{31}^{71} Ga$ (2) $_{38} S r^{84},_{38} S r^{86}$ (3) $_{42}^{92} Mo,_{40}^{92} Zr$ (4) $_{20} Ca^{40},_{16} S^{32} .$ 219. $The average binding energy of a nucleon inside an atomic nucleus is about$ (1) $8 MeV$ (2) $8 eV$ (3) $8 J$ (4) $8 erg$ 220. $Weak nuclear force always operates between$ (1) $electrons and neutrino$ (2) $heavier elementary particles$ (3) $charged particles$ (4) $all the objects in the universe$ 221. $Fission of nuclei is possible because the binding energy per nucleon in the$ (1) $increases with mass number at low mass numbers$ (2) $decreases with mass number at low mass numbers$ (3) $increases with mass number at high mass numbers$ (4) $decreases with mass number at high mass numbers$ 222. $The following is not used as a nuclear fuel.$ (1) $uranium$ (2) $thorium$ (3) $plutonium$ (4) $titanium$ 223. $The nucleus._{48}^{115} Cd after two successive β^{-} decays will give.$ (1) $_{46} P a^{115}$ (2) $_{49} ln^{114}$ (3) $_{50} S n^{113}$ (4) $_{50} S n^{115}$ 224. $Which of the following statements is true for nuclear forces?$ (1) $They obey the inverse square law of distance.$ (2) $They obey the inverse third power law of distance.$ (3) $They are short range forces.$ (4) $They are equal in strength to electromagnetic forces.$ 225. $Consider the following statements: (A) Atoms of each element emit characteristics spectrum. (B) According to Bohr's Postulate, an electron in a hydrogen atom, revolves in a certain stationary orbit. (C) The density of nuclear matter depends on the size of the nucleus. (D) A free neutron is stable but a free proton decay is possible. (E) Radioactivity is an indication of the instability of nuclei. Choose the correct answer from the options given below:$ (1) $A, B, C, D and E$ (2) $A, B and E only$ (3) $and only$ (4) $A, C and E only$ 226. $The phenomena in which proton flips is$ (1) $nuclear magnetic resonance$ (2) $lasers$ (3) $radioactivity$ (4) $nuclear fusion.$ 227. $The decay of a proton to neutron is:$ (1) $not possible as proton mass is less than the neutron mass$ (2) $possible only inside the nucleus$ (3) $not possible but neutron to proton conversion is possible$ (4) $always possible as it is associated only with β^{+} decay$ 228. $The life span of atomic hydrogen is$ (1) $fraction of one second$ (2) $one year$ (3) $one hour$ (4) $one day.$ 229. $The strongest force in nature is$ (1) $nuclear force$ (2) $gravitational force$ (3) $coulomb force$ (4) $frictional force$ 230. $Nuclear fission is best explained by$ (1) $liquid droplet theory$ (2) $Yukawa π ‐meson theory$ (3) $independent particle model of the nucleus$ (4) $proton‐proton cycle$ 231. $The particle having zero mass is$ (1) $proton$ (2) $neutron$ (3) $photon$ (4) $electron$ 232. $A radioactive nucleus has specific binding energy ' E_{1}'. It emits an α -particle. The resulting nucleus has specific binding energy ' E_{2}' Then$ (1) $E_{2} = E_{1}$ (2) $E_{2} < E_{1}$ (3) $E_{2} > E_{1}$ (4) $E_{2} = 0$ 233. $The energy equivalent of one atomic mass unit is$ (1) $1.6 \times 1 0^{- 19} J$ (2) $6.02 \times 1 0^{23} J$ (3) $931 MeV$ (4) $9.31 MeV$ 234. $Mass numbers of the elements A, B, C and D are 30, 60, 90, and 120 respectively. The specific binding energy of them are 5 MeV, 8.5 MeV, 8 MeV and 7 MeV respectively. Then, in which of the following reaction/s energy is released? (1) D \to 2 B (2) C \to B + A (3) B \to 2 A$ (1) $only in (1)$ (2) $in (2), (3)$ (3) $in (1), (3)$ (4) $in (1), (2) and (3)$ 235. $The relation between λ and T_{1/2} as (T_{1/2} \to half life)$ (1) $T_{1/2} = \frac{ln 2}{λ}$ (2) $T_{1/2} ln 2 = λ$ (3) $T_{1/2} = \frac{1}{λ}$ (4) $(λ + T_{1/2}) = ln 2.$ 236. $Solar energy is due to$ (1) $fusion reaction$ (2) $fission reaction$ (3) $combustion reaction$ (4) $chemical reaction$ 237. $Curie is a unit of$ (1) $energy of gamma rays$ (2) $half‐life$ (3) $radioactivity$ (4) $intensity of gamma rays$