Nuclei

Energy released when two deuterons (1H2 ) fuse to form a helium nucleus (2He4 ) is : (Given : Binding energy per nucleon of 1H2 = 1.1 MeV and binding energy per nucleon of 2He4 = 7.0 MeV)

1. 26.8 MeV
2. 8.1 MeV
3. 23.6 MeV
4. 5.9 MeV

Choose the correct nuclear process from the below options [p : proton, n : neutron, e- : electron, e+ : positron, : neutrino, : antineutrino]

1. n p + e+ +
2. n p + e- +
3. n p + e+ +
4. n p + e- +

A radioactive nucleus n2 has 3 times the decay constant as compared to the decay constant of another radioactive nucleus n1. If initial number of both nuclei are the same, what is the ratio of number of nuclei of n2 to the number of nuclei of n1, after one half-life of n1 ?

1. 1/4
2. 1/8
3. 4
4. 8

Given below are two statements. One is labelled as Assertion (A) and the other is labelled as Reason (R). In the light of the above statements, choose the correct answer from the options given below :

1. (A) is true but (R) is false
2. Both (A) and (R) are true and (R) is the correct explanation of (A)
3. (A) is false but (R) is true
4. Both (A) and (R) are true but (R) is NOT the correct explanation of (A)

The energy equivalent of 1 g of substance is :

1. 5.6 1026 MeV
2. 5.6 1012 MeV
3. 5.6 eV
4. 11.2 1024 MeV

A star has 100\% helium composition. It starts to convert three 4He into one 12C via triple alpha process as 4He + 4He + 4He 12C + Q. The mass of the star is 2.0 1032 kg and it generates energy at the rate of 5.808 1030 W. The rate of converting these 4He to 12C is n 1042 s-1, where n is . [Take, mass of 4He = 4.0026 u, mass of 12C = 12 u]

The energy released in the fusion of 2 kg of hydrogen deep in the sun is EH and the energy released in the fission of 2 kg of 235U is EU. The ratio EHEU is approximately: (Consider the fusion reaction as 4 11H + 2e- 24He + 2 + 6 + 26.7 MeV, energy released in the fission reaction of 235U is 200 MeV per fission nucleus and NA = 6.023 1023)

1. 7.62
2. 25.6
3. 9.13
4. 15.04

Binding energy of a certain nucleus is 18 108 J. How much is the difference between total mass of all the nucleons and nuclear mass of the given nucleus:

1. 20 g
2. 2 g
3. 10 g
4. 0.2 g

If M0 is the mass of isotope 125B, Mp and Mn are the masses of proton and neutron, then nuclear binding energy of isotope is:

1. (5Mp + 7Mn - M0)C2
2. (M0 - 5Mp - 7Mn)C2
3. (M0 - 5Mp)C2
4. (M0 - 12Mn)C2

In a hypothetical fission reaction 92X236 56Y141 + 36Z92 + 3R The identity of emitted particles (R) is :

1. Proton
2. Neutron
3. Electron
4. -radiations