The energy required in \(\mathrm{MeV} / \mathrm{c}^2\) to separate \({ }_8^{16} \mathrm{O}\) into its constituents is:
(Given mass defect for \({ }_8^{16} \mathrm{O}=0.13691 \mathrm{u}\))
1. \(127.5\)
2. \(120.0\)
3. \(222.0\)
4. \(119.0\)

A nuclear reaction is given by

${}_{\mathrm{Z}}{\mathrm{X}}^{\mathrm{A}}{\to }_{\mathrm{Z}+1}{\mathrm{Y}}^{\mathrm{A}}{+}_{-1}{\mathrm{e}}^0+\overline{\mathrm{v}}$

represents:

1. β-decay

2. γ-decay

3. fusion

4. fission

The mass number of a nucleus is:

The mass of a proton is 1.0073 u and that of a neutron is 1.0087 u (u = atomic mass unit). The binding energy of ${}_2{}^4\mathrm{He}$ is: (Given: helium nucleus mass ≈ 4.0015 u)

Which of the following rays are not electromagnetic waves?

1. X-rays

2. γ-rays

3. β-rays

4. Heat rays

A sample of a radioactive element has a mass of 10 gm at an instant t = 0. The approximate mass of this element in the sample after two mean lives is:

1. 1.35 gm

2. 2.50 gm

3. 3.70 gm

4. 6.30 gm

The half-life of a sample of a radioactive element containing 4 × 10¹⁶ active nuclei, is 10 days. The number of decayed nuclei after 30 days will be: 

1. $0.5\times {10}^{16}$

2. $2\times {10}^{16}$

3. $3.5\times {10}^{16}$

4. $1\times {10}^{16}$

Which of the following are suitable for the fusion process?

If the half-life of a radionuclide is 77 days, then its decay constant is:
1.  0.003/day
2.  0.006/day
3.  0.009/day
4.  0.012/day

A nucleus represented by the symbol ${}_{\mathrm{Z}}{}^{\mathrm{A}}\mathrm{X}$ has: