Nucleus Questions and Answers

A nucleus with mass number 240 breaks into two fragments each of mass number 120 the binding energy per nucleon of unfragmented nuclei is 7 6 MeV while that of fragments is 8 5 Me The total gain in the Binding Energy in the process

A nucleus with masa number 240 breaks into two fragmenta each of mass number 120 the binding energy per nucleon of unfragmented nuclei is 7 6 MeV while that of fragments is 8 5 MeV The total gain in the Binding Energy in the process is 1 804 MeV 216 MeV 0 9 MeV 9 4 MeV 4

The primary source of the sun s energy is a series of thermonuclear reactions in which the energy produced is c times the mass difference between A two hydrogen atoms and one helium atom B four hydrogen atoms and one helium atom C six hydrogen atoms and two helium atoms D three helium atoms and one carbon atom

34 the nucleus 235 92Y initially at rest decays into 231 90 X by emitting an a particle 235 231 4 92 90 2 Y X He energy The binding energies per nucleon the daughter nucleus and a particle are 7 8 MeV 7 835 MeV and 7 07 Mev Respectively Assuming the daughter nucleus to be formed in the unexcited state and neglecting its share in the energy of the reaction find the speed of the emitted a particle Mass of a particle 6 68x10 27 kg

The mass number of a nucleus is A always less than its atomic number always more than its atomic number C equal to its atomic number D Sometimes more than and sometimes equal to its atomic numbe

At a given instant sat t 0 two radioactive substances A and B have equal activities The ratio RB RA of their activities after time t itself decays with time t as e 3t If the half life of A is In 2 the half life of B is O O O In 2 2 2 In 2 In 2 4 4 In 2

the wrong statement A The nuclear force becomes weak if the nucleus contains too many protons compared to the numbe of neutrons The nuclear force becomes weak if the nucleus contains too many neutrons compared to th number of protons C Nuclei with atomic number greater than 82 show a tendency to disintegrate The nuclear force becomes very strong if the nucleus contains a large number of nucleons

A nucleus with A 240 has a binding energy of 7 5 MeV per nucleon When it splits into two fragments of equal mass 240 MeV of energy is released The binding energy per nucleon of the daughter neuclei is A 9 5 MeV B 8 5 MeV C 6 5 MeV MOV ed TOMMAD

2 3 A certain element decays in two different ways it shows alpha decay with a half life of In 2 years and with beta decay it has a half life of In 4 years After how many year will a pure sample of 100 mg of the elemen would have 50 mg of that element 2 0 46 years 4 1 25 years 1 0 52 years 3 0 75 years

a Two large conducting spheres carrying charges 9 and 9 are brought close to each other Is the magnitude of electrostatic force between them exactly given by 9 9 4 where r is the distance between their centres b If Coulomb s law involved 1 r dependence instead of 1 r would Gauss s law be still true c A small test charge is released at rest at a point in an electrostatic field configuration Will it travel along the field line passing through that point d What is the work done by the field of a nucleus in a complete circular orbit of the electron What if the orbit is elliptical

A neutron is 0 0014 u heavier than a proton An isotope of Nitrogen 5N has a mass of 15 00011 u while its mirror nucleus 150 has a mass of 15 00331 u If E and E respectively represent the total binding energies of 5N and 150 nuclei then it follows that A E E 0 B E E 0 248 MeV C E E 4 28 MeV D EN E 4 28 MeV

d 1 5 A radioactive nucleus of mass M emits a photon of frequency n and the nucleus recoils The recoil energy will be 2011 Pre a Mc 2 hv c Zero b h v 2Mc d hv

26 A certain mass of Hydrogen is changed to He lium by the process of fusion The mass defect in fusion reaction is 0 02866 a m u The energy 2013 liberated per a m u is Given 1 a m u 931 MeV a 26 7 MeV c 13 35 MeV b 6 675 MeV d 2 67 MeV 34

3 The half life period for catalytic decomposition of AB at 50 mm is found to be 4 hrs and at 100 mm it is 2 hrs The order of reaction is 1 3 3 2 2 1 4 0

larks TE KE Attempt All 35 questions Which of the following is incorrect related to energy of a satellite KE PE 2 B E IT E I None of these View In Q English CHU

A given sample has two radioactive nuclei C and D The half life of species D is 1 68 days whereas that one of C is unknown Initially they are present in equal amounts Five days later there are five times as many C nuclei as there are D nuclei Calculate the half life of species C Androg

50 180 The binding energies of nuclei A and B are K and K respectively Four nuclei of A fuse to give one nuclei of B and energy released is Q The correct relation of Q with K and K will be Q K K XQ 4K K Q K K

c William Crookes d J J Thomson 3 The specific charge of a proton is 9 6 x 10 C kg The specific charge of an alpha particle will be b 19 2 x 10 Ckg a 9 6 x 10 C kg c 4 8 x 10 C kg d 2 4 x 10 Ckg

A beam of pions 7 is incident on a proton target giving rise to the process n A Assuming that the decay proceeds through strong interactions the total isospin I and its third component I3 for the decay products are 3 a I I 2 c I 5 2 1 3 2 3 N W 2 5 b I 1 2 d I 13 2 5 2 2

How much mass of uranium to be destroyed per 30 600 alla fy minute to operate a nuclear reactor of 600 MW a fel ca 1 400 g 2 400 mg 4 400 kg 3 400 g 1 Four particles of masses m 2m m 4m m m and m are placed at four corners of a square What should be the value of m so that the 50 31 1 400 g 3 400 g 2 400 mg 4 400 kg m4 titur ferdim I GUIE SOHA m 2m m 4m m m fauf

and n particles Here n is A B 7 3 4 6 Unans

34 180 When two nuclei with A 4 joined to form a heavier nucleus t binding energy per nucleon of heavier nuclei is More than the BE per nucleon of lighter nuclei Same as the BE per nucleon of the lighter nuclei O Less than the BE per nucleon of the lighter nuclei O Double the BE per nucleon of lighter nuclei

28 180 Mark for Review During a 3 minus decay O An atomic electron is ejected 02 56 hr mir A neutron in the nucleus decays emitting ar electron A part of binding energy is converted into electron An electron which is already present in nucleus is ejected

Fission of nuclei is possible because the binding energy per nucleon in them Increases with mass number at high mass numbers Decreases with mass number at high mass numbers Increases with mass number at low mass numbers O Decreases with mass number at low mass numbers Marks 4

An atomic electron is ejected A neutron in the nucleus decays emitting an electron A part of binding energy is converted into electror An electron which is already present in nucleus is ejected

When two nuclei with A 4 joined to form a heavier nucleus the binding energy per nucleon of heavier nuclei is More than the BE per nucleon of lighter nuclei Same as the BE per nucleon of the lighter nuclei Less than the BE per nucleon of the lighter nuclei O Double the BE per nucleon of lighter nuclei

the ratio of energies of photons produced due to transition of an electron of hydrogen atom from its i second permitted energy level to the first permitted level and ii the highest permitted energy level to the first permitted level 20101

O Only A Consider the following two statements Statement A The average kinetic energy per degree of freedom per molecule at a given temperature increases as degrees of freedom increase Statement B The ratio of molar specific heat at constant pressure to that at constant volume increases as the atomicity increases The correct statement is O Only B O Both A and B E Neither A nor B mir

An a particle with a kinetic energy of 2 1 eV makes a head on collision with a hydrogen atom moving towards it with a kinetic energy of 8 4 eV The collision A must be perfectly elastic C may be inelastic B may be perfectly inelastic D must be perfectly inelastic

3 Answer the following questions which help you to understand the difference between Thomson s model and Rutherford s model better a Is the average angle of deflection of a particles by a thin gold foil predicted by Thomson s model much less about the same or much greater than that predicted by Rutherford s model b Is the probability of backward scattering i e scattering of a particles at angles greater than 90 predicted by Thomson s model much less about the same or much greater than that predicted by Rutherford s model HOUT JUO TO c Keeping other factors fixed it is found experimentally that for small thickness t the number of a particles scattered at moderate angles is proportional to t What clue does this linear dependence on t provide nm to d In which model is it completely wrong to ignore multiple scattering for the calculation of average angle of scattering of a particles by a thin foil

2 It is necessary to apply quantum statistics to a system of particles if a there is substantial overlap between the wave functions of the particles b the mean free path of the particles is com parable to the inter particle separation c the particles have identical mass and charge d the particles are interacting

meson hydrogen atom in a bound state of negatively charged pion mass of pion 27 times mass of electrons and a proton If the number of revolutions a meson makes x x 1010 in the ground state of the atom before it decay mean life of a meson 10 8 sec Question Type Multiple Correct Type 1 For n 1 radius of meson atom will be 1 94 x 10 13 m n 2 For n 1 velocity in nth orbit is 2 18 106 m s 3 Time of one revolutions is 5 6 10 19 s 4 Number of revolutions before meson

A vessel of 831cc contains H at 0 6 atm and 27 C If half life of H is 12 3 years then the activity of the gas is Question Type Multiple Correct Type 1 2 3 3 04 x 1013 dps 582 Ci 2 15 10 3 dps

12 A heavy nucleus X of mass number 240 and binding energy per nucleon 7 6 MeV is spil two fragments Y and Z of mass numbers 110 and 130 The binding energy per nucken and Z is 8 5 MeV per nucleon Calculate the energy Q released per fission in MeV

FISS Fission of nucle is possible because the binding energy per nucleon in them D AIPMT Prelims 2005 1 Increases with mass number at high mass numbers 2 Decreases with mass number at high mass numbers 3 Increases with mass number at low mass numbers 4 Decreases with mass number at low mass

Five equal resistances each of resistance R are connected as shown in the figure A battery of V volts is connected between A and B The current flowing in AFCEB will be 2004 A B FC D FEVR NL 3V 2R 2V D R MMM www R R AB E

A particular smoke detector contains 1 45 Ci of 241 Am with a half life of 458 years The isotope is encased in a thin aluminum container Calculate the mass of 241 Am in grams in the detector Express your answer numerically in grams

40 At time t 0 some radioactive gas is injected into a sealed vessel At time T some more mass of the same gas is injected into the same vessel Which one of the following graphs best represents the variation of the logarithm of the activity A of the gas with time t In A In A a c In A b d In A T

The wavelength of the first line of Lyman series for hydrogen atom is equal to that of the second line of Balmer series for a hydrogen like ion The atomic number Z of hydrogen like ion is 1 3 2 4 3 1 4 2

View In English The count rate for 10 gm of radioactive material was measured at different times and this has been shown in the graph with scale given The half life of the material and the total count in the first half value period respectively are 100 2 4 4 hour and 9000 approximately 3 hour and 14100 approximately 3 hour and 235 approximately 10 hour and 150 approximately Correct Answer 2 Status unattempted Count rate per minute 75 25 12 5 45678910 Time in hours

6 A uranium 238 nucleus initially at rest emits an alph particle with a speed of 14 x 10 m s Calculate the recoil speed of the residual nucleus thorium 234 Assume that the mass of a nucleus is proportional to the mass number

Consider a nuclear reaction A B C A nucleus A moving with kinetic energy of 5 MeV collides with a nucleus B moving with kinetic energy of 3 MeV and forms a nucleus C in the exited state with 5 3 excitation energy 10 MeV The kinetic energy of nucleus C just after its formation is MeV P Take masses of nuclei of A B and C as 25 amu 10 amu and 34 995 amu respectively and lamu 930 MeV c Find value of p

3 Polonium emits an a particle a Calculate the maximum height of the barrier for the a particle within the nucleus b Using P exp 4 0ZDQ 9 3x107 ZDR 2 as the probability of transmission through the barrier calculate the half life T1 2 Q is in MeV and R in meter Hint R R Ra

Let Fpp Fpn and Fan denote the nuclear force between proton proton proton neutron and neutron neutron pair respectively When separation is 1 fm Fpp Fpn Fnn O Fpp Fpn Fnn O Fpp Fpn Fnn

A potential difference of 20 kV is applied across an X ray tube Find the minimum wavelength of X rays generated A skipped C 0 62 A 0 65 A 6 62 A

the After two alpha decays and four beta ve decays the atomic number 1 Decreases by 4 and mass number remains same 2 Remains the same but the mass number increases by 4 3 Remains same but mass number decreases by 8 4 Increases but mass number remains same

2 5 Half life of radioactive substance is 3 20 h What is the time taken for a 75 of substance to be used 6 38 h O 12 h 4 1 00 12 O4 18 days

The rest mass of an electron as well as that of positron is 0 51 MeV When an electron and positron are annihilate they produce gamma rays of wavelength s O O 0 012 0 024

Two samples X and Y contain equal amount of 1 radioactive substances If 16th of the sample 1 X and 256 of the sample Y remain after 8 hours then the ratio of half periods of X and Y is Question Type Single Correct Type 1 2 3 2 1 1 2 1 4

binding energy per nucleon in them Question Type Single Correct Type 1 2 3 4 Increases with mass number at high mass numbers Decreases with mass number at high mass numbers Increases with mass number at low mass numbers Decreases with mass number at low mass numbers