1. | \(25:16\) | 2. | \(1:1\) |
3. | \(4:5\) | 4. | \(5:4\) |
1. | \(\beta^{+}, ~\alpha, ~\beta^{-}\) | 2. | \(\beta^{-}, ~\alpha, ~\beta^{+}\) |
3. | \(\alpha, ~\beta^{-},~\beta^{+}\) | 4. | \(\alpha, ~\beta^{+},~\beta^{-}\) |
A nucleus with mass number \(240\) breaks into fragments each of mass number \(120\). The binding energy per nucleon of unfragmented nuclei is \(7.6~\text{MeV}\) while that of fragments is \(8.5~\text{MeV}\). The total gain in the binding energy in the process is:
1. \(804~\text{MeV}\)
2. \(216~\text{MeV}\)
3. \(0.9~\text{MeV}\)
4. \(9.4~\text{MeV}\)
If a species emits firstly a positron, then two and two β and at last one is also emitted and finally convert into stable species, so the correct relation will be:
1. c = b – 12, d = a – 5
2. a = c – 8, d = b – 1
3. a = c – 6, d = b – 0
4. a = c – 4, a = b – 2
A nuclear reaction is given by
represents:
1. β-decay
2. γ-decay
3. fusion
4. fission
The mass number of a nucleus is:
1. | always less than its atomic number. |
2. | always more than its atomic number. |
3. | sometimes equal to its atomic number. |
4. | sometimes less than and sometimes more than its atomic number. |
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 is: (Given: helium nucleus mass ≈ 4.0015 u)
1. | 0.0305 J | 2. | 0.0305 erg |
3. | 28.4 MeV | 4. | 0.061 u |
Which of the following rays are not electromagnetic waves?
1. X-rays
2. γ-rays
3. β-rays
4. Heat rays
The volume occupied by an atom is greater than the volume of the nucleus by a factor of about:
1. \(10\)
2. \(10^5\)
3. \(10^{10}\)
4. \(10^{15}\)