Nucleus Questions and Answers

In a hydrogen atom following Bohr s postulates the product of linear momentum and angular momentum is proportional to n where n is the orbit number Then x is H 1 2 3 1 2 0 4 2 IC

An electron and proton are separated by a large distance and the electron approaches the proton with an initial kinetic energy of 2 9eV The electron is captured by the proton to form a hydrogen atom in the ground state If the wavelength in nm of the photon given off is 15 X find the value of X

Consider the following reaction H H He Q If m H 2 0141u and m He 4 0024 u the energy Q released in MeV in this fusion reaction is nearly 24 MeV 20 MeV 12 MeV 10 MeV

231U decays to 2 Pa The proposed mode is decay or K shell capture The masses are 92 91 Pa M 231 03621 amu Mpa 231 03588 amu mass of electron 0 51 MeV C 1 amu 931 MeV C Neglect the mass of neutrino emitted 231U can decay by A K shell capture decay both C pt decay but not K shell capture B K shell capture but not decay D Neither decay nor K shell capture

Average binding energy per nucleon is constant and is equa to 8 MeV per nucleon for most of the nuclei This is because nuclear force Is long range force Is charge dependent Is central force Shows saturation property

Let Fpp FPn and Fnn denote the magnitudes of the net force by a proton on a proton by a proton on neutron and by a neutron on a neutron respectively Neglecting the gravitational force when the separation is 1 fm then choose the correct option Fpp Fen Fnn O Fpp Fen Fnn Fpp Fpn Fnn

2 1 The natural boron of atomic mass 10 81 u is found to have two isotopes 08 and B The ratio of abundance of isotopes of natural boron should be nearly NCERT Pg 439 2 1 11 10 2 81 19 3 10 11 4 19 81 The energy liberated in a single uranium

17 A nucleus with mass number 220 initially at rest emits an a particle If the Q value of reaction is 5 5 MeV the kinetic energy of a particle is NCERT Pg 449 1 4 4 MeV 2 5 4 MeV 3 5 0 MeV 4 4 8 MeV 19

measured by electron scattering is 3 6 fm What is the mass number of the nucleus most likely to be NCERT Pg 441 1 27 3 56 2 40 4 120

ALLEN 117 35 In a fission reaction 336 U 7 X 7 Y n 92 the binding energy per nucleon of X and 8 5 MeV whereas of 236U is 7 6 MeV The energy liberated will be about 1 200 KeV 2 2 MeV 3 300 May 4 2000 MeV

If the size of atom which is of order of 10 10 m is scaled up to the tip of sharp pin then rough estimate of size of nucleus is Assume tip of pin to be of order of 10 6 m and nuclear size to be of order of 10 15 m O 0 1 O 0 001 O 100 O 10

vx105 ms 2 55 4 35 5 20 Out of electron proton which one will have a higher velocity to produce matter waves the same wavelength Explain it What is the difference in the origin of cathode rays and anode rays

3 The ionization energy of the electron in the hydrogen atom in its ground state is 13 6 eV The atoms are excited to higher energy levels to emit radiations of 6 wavelengths Maximum wavelength of emitted radiation corresponds to the transition between 1 n 4 to n 3 states 2 n 3 to n 2 states 121 1 4

10 Na23 being unstable decay into stable Na23 If the nuclear mass are m 0Na23 22 994466 amu m Na23 22 989770 amu and mass of electron 0 000545 amu then find the approximate kinetic energy of the emitted electron 1 2 236 MeV 3 4 374 MeV 2 4 022 MeV 4 3 863 MeV

NEET UG 2019 Odisha The radius of the first permitted Bohr orbit for the electron in a hydrogen atom equals 0 51 A and its ground state energy equals 13 6 eV If the electron in the hyrogen atom is replaced by muon u charge same as electron and mass 207 mel the first Bohr radius and ground state energy will be 1 0 53 x 10 13 m 3 6 eV 2 25 6 x 10 13 m 2 8 eV 3 2 56 10 13 m 2 8 keV 4 2 56 10 13 13 6 eV P m MROM

The electric quadrupole moment of a nuclear charge distribution which is of the shape of an 270 ellipsoid is given by p b a Total nuclear charge Ze Average nuclear radius R a b b R R bis semi major axis a is semi minor axis Mark the CORRECT statement s under condition OR R A a R 1 R C P 6Ze R SR Ra R R B b a 3R D P 27e R 5 SR R SR R

For a CE transistor amplifier the audio signal voltage across the collector resistance of 1 KQ is 4 0 V Suppose the current amplification factor of the transistor is 100 If the dc base current has to be 10 times the signal current then the value of RB in series with VBB supply of 4 0 V will be Take VBE 0 6 V 1440

2 Consider the following two statements a The binding energy per nucleon is practically independent of mass number for nuclei of middle mass number 30 A 170 b Binding energy per nucleon is lower for both light nuclei A 30 and heavy nuclei A 170 The correct statement s is are 1 Only a 3 Both a and b 2 Only b 4 Neither a nor b

the ratio of Population of the two states in He Ne laser that Produces light of wavelength 6328 Ao at 27 o C Option 1 2 1 x 10 29 Option 2 1 24 x 10 30 Option 3 2 1 x 10 27 Option 4 1 1 x10 33

16 The particle antineutrino released during electron decay satisfies the law of conservation of 1 Mass energy 2 Linear momentum 3 Spin angular momentum 4 All of these

nudeon 16 Which of the following are correct for binding energy per uneleon AEbn AE curve plotted as a function of mass number A a Maximum occurs A 50 CA b When A increases from 0 to 30 there are considerable fluctuations as internucleon interaction is largely affected by pairing and symmetry effects bn c For A 30 AEn varies only about 10 This shows nucleus interacts with their neighbours only d For A 50 the mean binding energy per nucleon decreases because of coulombic repulsion 80

The nucleus 92 U234 splits exactly in half in a fission reaction in which two neutrons are released The resultant nuclei are UPSEAT 2004 a Pd116 c 45 Rh 16 b d 45 Rh117 Pd 17 46

19 Cadmium and Boron rods are used in a nuclear reactor to 1 slow down neutrons 2 absorb excess number of thermal neutrons 3 speed up neutrons 4 absorb fast neutrons 20 A p n junction diode has breakdown voltage of 28 V If applied external voltage in reverse bias is 40 V the current through it is 1 0 7 A 2 1 4 A 3 zero 4 infinite

The energy of a photon is equal to the kinetic energy of a proton The energy of photon is E If be the de Broglie wavelength of the proton and X be the wavelength of photon The ratio of is proportiona to 1 3 E A car approaching a crossing at a speed of 30 m s 2 E 4 E

and carrying a magnetic moment The system is immersed in a magnetic 90 The ideas of statistical mechanics induction field B Each particle may then exist in one of the two energy states a spin down state of energy B and a spin up state of energy B Treat the particles as being distinguishable Derive a formula for the entropy in terms of the number of particles in the upper state n Sketch S n Find the value of n for which S n is a max imum What is the relation between S and the temperature By treating the energy as a continuous variable show that the system can have nega tive temperatures If a system with a negative temperature makes thermal contact with one with a positive temperature which way will the heat flow

D The binding energy per nucleon of deuteron and a particles are X and x2 respectively The energy released in the following reaction will be 1H 1H 2He4 Q 1 x1 x2 3 2 x1 x2 2 x2 x1 4 4 x2 x1

Two radioactive elements R and S disintegrate as R P AR 4 5 10 1 years As 3 10 years Starting with number of atoms of R and Sin the ratio of 5 1 this ratio after the lapse of three half lives of R will be

The binding energy per nucleon for C 2 is 7 68 MeV and that for C 3 is 7 5 MeV The energy required to remove a neutron from C13 is Question Type Single Correct Type 1 5 34 MeV 2 5 5 MeV 3 9 5 MeV 4 9 34 MeV

4 Half life of a radioactive substance A is two times the half life of another radioactive substance B Initially the number of nuclei of A and B are NA and NE respectively After three half lives of A number o nuclei of both are equal Then the ratio NA NB is 5 1 4 c 1 3 b 1 8 d 1 6

Beta plus decay is shown below Assuming that X and Y both are neutral atoms and energy carried by vis negligible the Q value of the process is e v AY 2m Jc XAY 1 m X m 2 m X m Y c 3 m X m AY m c 4 m X m Y m c

Mass numbers of the elements A B C and 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 ii C B A i D 2B iii B 2A a only in i c in i iii b in ii iii d in i ii and iii

Which of the following statement s is are correct A The rest mass of a stable nucleus is less than the sum of the rest masses of its separated nucleons B The rest mass of a stable nucleus is greater than the sum of the rest masses of its separated nucleons C In nuclear fusion energy is released by fusing two nuclei of medium mass approximately 100 amu D In nuclear fission energy is released by fragmentation of a very heavy nucleus

3 676 66 mm 4 5766 6 nm 9 Pure Si at 500 K has equal number of electron n 29 and hole n concentrations of 1 5 x 10 m Doping by indium increases n to 4 5 x 102 m The doped semiconductor is of 0 1 p type having electron concentration n 5 x 10 m concentration 2 n type with electron n 5 x 10 m 3 p type with electron n 2 5 x 10 m concentration concentration 4 n type with electron n 2 5 x 10 m The temperature of furnace is 200 C in its 30 3 676 66 nm 500 K of fuera 1 2 n 3 4 5766 6 mm fasta n a n R 1 5 x 10 m 1 sfamat 4 5 x 10 m n 5 x 10 mi fenen n 5 x 10 m ti 4 n n 2 5 x 100 m ti 2 5 x 10 m 200

In a radioactive decay A is converting into B and B is converting into C It is given that t Onuclei of B and C are not present decay constant for A to B is and decay constant for B to C is take 52 and 22 The time after which B will have maximum No of nuclei is of the form ln 5 2 Bo Then value of B will be A 5 2 B 3 C 2 5 D 2 A i B 2 C

3 10 2 4 24 2 Two large parallel plates are connected with the terminal of 100 V power supply These plates have a fine hole at the centre An electron having energy 200 eV is so directed that it passes through the holes When it comes out its de Broglie wavelength will be 200 eV 1 1 22 3 2 3 100 V 2 1 75 4 None of these 9 3 10 2 4 24 2 act TARK VIC100 VELIT fox 1 200 eV fo care fac s arcia 200 eV 1 1 22 3 2 3 100 V 2 1 75 4 None of these

A neutron with kinetic energy of T 10 Mev activates a nuclear reaction n C4 Be a whose threshold energy is Th 6 17 Mev The K E approx value of a particle if a particle move at right angle to the direction of neutron will be A 1 21 MeV B 2 21 MeV C 4 1 MeV D None of these

bit to third Bohr orbit Find the value of Z b De Consider the following fussion reaction H H 2He If 20 MeV of energy is released p fusion reaction Mass of H2 consumed per day is 0 1 gm What is the Power of the reactor MW

The radioactive sources A and B of half lives of 2hr and 4hr respectively initially contain the same number of radioactive atoms At the end of 2 hours their rates of disintegration are in the ratio O 4 1 O 2 1 O 2 1 011

A normal stationary lithium atom releases an alpha particle with velocity 21 31 7k km s What will be the velocity of the daughter element just after the release of the alpha particle O 1 2 21 31 7k km s 4 3 21 31 7k km s 1 4 21 31 7k km s O 1 5 21 31 7k km s

The emitted 13 particle by a radioactive atom is an electron which is D Emitted from the orbit of the atom Already present in the nucleus O Produced by the conversion of neutron into proton in the nucleus O Produced by the conversion of proton into neutron in the nucleus

Consider two nuclei of the same radioactive nuclide One of the nuclei was created in a supernova explosion 5 billion years ago The other was created in a nuclear reactor 5 minutes ago The probability of decay during the next time is 1 Different for each nuclei 2 Nuclei created in explosion decays first 3 Nuclei created in the reactor decays first 4 Independent of the time of creation

10 10 3 A 175 4 225 A 12 In the given nuclear reaction A B C D E represents 920238 Th Pa E 234 1 A 234 B 90 C 234 D 91 E B 2 A 234 B 90 C 238 D 94 E x 3 A 238 B 90 C 234 D 91 E B 4 A 234 B 90 C 234 D 93 E x 13 Half lives of two radioactive substances A and B are 13 10 175 10 4 A 225 A B C D E 9 234 92U238 Th Pa E 1 A 234 B 90 C 234 D 91 E B 2 A 234 B 90 C 238 D 94 E a 3 A 238 B 90 C 234 D 91 E 4 A 234 B 90 C 234 D 93 E a 20 3 A 12 fff a

Two nuclei have their mass numbers in the ratio of 1 3 the ratio of their nuclear densities would be Question Type Single Correct Type 1 2 3 31 3 1 1 1 1 3

Q 12 A nucleus with mass number 184 initially at rest emits an a particle If the Q value of th reaction is 5 5 MeV calculate the kinetic energy of the a particle ptions 1 5 0 MeV 2 5 5 MeV 3 5 38 MeV 4 0 12 MeV

Three physical quantities are listed in list I and their values are listed in list II in random order List l List II P Binding energy of heavy nuclei per nucleon 1 10 keV Q X ray photon energy 2 7 MeV R Photon energy of visible light 3 2 eV

244s He is told that the air in the tube has been replaced by another gas assume that the column remair filled with the gas If the minimum height at which resonance occurs is 0 350 0 005 m the gas in the tub is Useful information 167RT 640j 2 mole 1 2 140RT 590j 2 mole 1 2 The molar masses M for each gas as given there grams are given in the options Take the value of 10 M A Neon M 20 B Nitrogen M 28 C Oxygen M 32 10 7 20 10 A 3 M 20 10 28 10 9 32 16 10 17 36 32 D Argon M 36 y faceff ym 31714 kam dyn ym zaRa tuning fork 35 244 s 34 u aid gy v ju I ar tufay rea G4 1 4 5 HE DY Km Ha u H I HR RED Raffay 0 350 005 167RT 640j1 2 mole 1 2 140RT 590j 2 mol 1 2 T PAY A 10 7 20 10 10 VM i fui qui c t v B M 28 10 28 35 47

The radioactive sources A and B of half of 2hr and 4hr respectively initially conta same number of radioactive atoms At th of 2 hours their rates of disintegration the ratio 1 4 1 Electrons 2 2 1 3 2 1 4 used in an electron microscop

50 A radioactive nucleus X undergoes a decay to form Y Y undergoes an a decay to form Z Under this transformation A The mass number of Z is higher than the mass number of X by 2 B The mass number of Z is lower than the mass number of X by 2 C The atomic number of Z is higher than the atomic number of X by 1 D The atomic number of Z is lower than the atomic number of X by 1 JENPARH P C 8 6 of 22

100 At time 0 a container has N radioactive atoms with a decay constant 2 In addition e numbers of atoms of the same type are being added to the container per unit time How many alons of this type are there at 7 exp 17 N exp 27 B A exp 17 N exp 27 C 1 exp 17 N exp AT D 1 exp 17 No exp AT A

A small quantity of containing Na24 radio nuclide half life 15 hour of activity 1 0 micro curie is injected into the blood of a person A sample of the blood of volume 1cm taken after 5 hour shows an activity of 296 disintegration per minute Determine the total volume blood in the body of the person Assume that radioactive solution mixes uniformly in the blood of the person 1curie 3 7 10 0 disintegration per second