Solar energy is mainly caused due to:
1. | burning of hydrogen in the oxygen |
2. | fission of uranium present in the sun |
3. | fusion of protons during synthesis of heavier elements |
4. | gravitational contraction |
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. \(10^{15}\)
1. | \(0.0305\) J | 2. | \(0.0305\) erg |
3. | \(28.4\) MeV | 4. | \(0.061\) u |
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. |
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
The energy released in nuclear fission is due to:
1. | some mass is converted into energy |
2. | the total binding energy of fragments is more than the B.E. of the parental element |
3. | total B.E. of fragments is less than the B.E. of parental element |
4. | total B.E. of fragments is equal to the B.E. of parental element |
represent the mass of the neutron and proton respectively. An element having mass M has N neutrons and Z-protons, then the correct relation will be:
1.
2.
3.
4.