Nuclei

Two radioactive substances A and B of mass numbers 200 and 212 respectively, shows spontaneous -decay with same Q value of 1 MeV. The ratio of energies of -rays produced by A and B is .

1. 25482650
2. 27062646
3. 25972600
4. 28622499

The energy released when 717.13 kg of 37Li is converted into 24He by proton bombardment is 1032 eV. The value of is . (Nearest integer) (Mass of 37Li=7.0183 u, mass of 24He=4.004 u, mass of proton =1.008 u and 1 u =931 MeV/c2 and Avogadro number =6.0 1023)

The energy released if hydrogen atoms are combined to form 24He is MeV. (Take binding energies per nucleon of 12H and 24He as 1.1 MeV and 7.2 MeV, respectively)

1. 6.1
2. 24.4
3. 26.6
4. 5

Assuming the experimental mass of 612C as 12 u, the mass defect of 612C atom is MeV/c2. (Mass of proton = 1.00727 u, mass of neutron = 1.00866 u, 1 u = 931.5 MeV/c2 and c is the speed of the light in vacuum).

1. 127.5
2. 89.03
3. 272.0
4. 92.0

Two nuclei of mass number 3 combine with another nucleus of mass number 4 to yield a nucleus of mass number 10. If the binding energy per nucleon for the mass numbers 3, 4 and 10 are 5.6 MeV, 7.4 MeV and 6.1 MeV, respectively, then in the process, Mc2= MeV.

1. 6.9
2. 7.9
3. 2.2
4. 4.3

The binding energy per nucleon of 20983Bi is MeV. [Take m( 20983Bi) = 208.980388 u, mp = 1.007825 u, mn = 1.008665 u, 1 u = 931 MeV/c2]

1. 7.48
2. 7.84
3. 8.79
4. 6.94

An atom 83X is bombarded by shower of fundamental particles and in 10 s this atom absorbed 10 electrons, 10 protons and 9 neutrons. The percentage growth in the surface area of the nucleus is recorded by :

1. 150\%
2. 900\%
3. 125\%
4. 225\%

A nucleus has mass number and radius R . Another nucleus has mass number and radius R . If = 8 then R /R is :

1. 1
2. 2
3. 8
4. 0.5

Given below are two statements : In the light of the above statements, choose the correct answer from the options given below

1. Statement I is false but Statement II is true
2. Both Statement I and Statement II are true
3. Both Statement I and Statement II are false
4. Statement I is true but Statement II is false

The binding energies for the following nuclear reactions are expressed in MeV. 2He3 + 0n1 2He4 + 20 MeV 2He4 + 0n1 2He5 - 0.9 MeV If X3, X4, X5 denote the stability of 2He3, 2He4 and 2He5, respectively, then the correct order is :

1. X4 > X5 > X3
2. X4 < X5 < X3
3. X4 > X5 < X3
4. X4 = X5 = X3