CBSE Physics Atom, Molecule, Nuclei Expected Questions : Unit X
Derivation Type/Numerical Type Questions (3 Marks Questions)
1. 92U238 decays successively to form 90Th234, 91Pa234, 92U234; 9oTh230, 88Ra226 and 86Rn222 What are the radioactive radiations emitted in each decay process ?
Answer
2. Define hah0 life period of a radioactive substance. Establish its relationship with decay constant.
Answer
3. How photons which are positively charged, held together inside a nucleus ? Draw a graph between potential energy of a pair of nucleons as a functions of their separation.
Answer
4. The half life of a radioactive substance is 1.192x107 s against alpha decay. Calculate the decay rate for 3.18 X 1015 atoms of the substance.
Answer
5. Explain generation of energy in nuclear fusion reaction.
Answer
6. Draw a graph shown of variation of binding energy per nucleon with mass number. Write two main inferences from the graph.
Answer
7. Will neutron to proton ratio increase or decrease, when a radioactive nucleus emits (i) alpha particle, (ii) a beta particle ? Give one example in each case in support of your answer.
Answer
8. Explain the emission of y rays with an example.
Answer
9. What is meant by ionisation and excitation potential ?
Answer
10. How much energy is produced when a mass of 1 amu is completely destroyed ?
Answer
11. What is meson theory of nuclear forces ?
Answer
12. Derive a relation of K.E. of alpha particle in terms of total energy of nucleus from where it is emitted.
Answer
13. Neutrons produced in fission can be slowed even by using ordinary water. Then water is heavy water used for the purpose ?
Answer