Fast neutrons can easily be solved down by
- the use of lead shielding
- passing them through water
- elastic collision with heavy nuclei
- applying a strong electric field
The Correct Option is B
Solution and Explanation
Commonly used moderators include regular (light) water (roughly $75 \%$ of the world's reactors), solid graphite ( $20 \%$ of reactors) and heavy water.
Top Questions on Nuclear physics
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): The density of the copper ($^{64}Cu$) nucleus is greater than that of the carbon ($^{12}C$) nucleus.
Reason (R): The nucleus of mass number A has a radius proportional to $A^{1/3}$.
In the light of the above statements, choose the most appropriate answer from the options given below:- JEE Main - 2025
- Physics
- Nuclear physics
Match the LIST-I with LIST-II
\[ \begin{array}{|l|l|} \hline \text{LIST-I} & \text{LIST-II} \\ \hline A. \ ^{236}_{92} U \rightarrow ^{94}_{38} Sr + ^{140}_{54} Xe + 2n & \text{I. Chemical Reaction} \\ \hline B. \ 2H_2 + O_2 \rightarrow 2H_2O & \text{II. Fusion with +ve Q value} \\ \hline C. \ ^3_1 H + ^2_1 H \rightarrow ^4_2 He + n & \text{III. Fission} \\ \hline D. \ ^1_1 H + ^3_1 H \rightarrow ^4_2 H + \gamma & \text{IV. Fusion with -ve Q value} \\ \hline \end{array} \]
Choose the correct answer from the options given below:
- JEE Main - 2025
- Physics
- Nuclear physics
Match the following types of nuclei with examples shown:
- KCET - 2025
- Physics
- Nuclear physics
- For a nucleus of mass number $ A $ and radius $ R $, the mass density of the nucleus can be represented as:
- JEE Main - 2025
- Physics
- Nuclear physics
- For a nucleus of mass number $A$ and radius $R$, mass density $\rho$. Then choose the correct option.
- JEE Main - 2025
- Physics
- Nuclear physics
Questions Asked in BITSAT exam
- A particle of mass \( 2 \) kg is on a smooth horizontal table and moves in a circular path of radius \( 0.6 \) m. The height of the table from the ground is \( 0.8 \) m. If the angular speed of the particle is \( 12 \) rad/s, the magnitude of its angular momentum about a point on the ground right under the center of the circle is:
- BITSAT - 2024
- General Principles and Processes of Isolation of Elements
Evaluate the following limit: $ \lim_{n \to \infty} \prod_{r=3}^n \frac{r^3 - 8}{r^3 + 8} $.
- BITSAT - 2024
- limits and derivatives
- Inside a solenoid of radius \( 0.5 \) m, the magnetic field is changing at a rate of \( 50 \times 10^{-6} \) T/s. The acceleration of an electron placed at a distance of \( 0.3 \) m from the axis of the solenoid will be:
- BITSAT - 2024
- thermal properties of matter
In the given cycle ABCDA, the heat required for an ideal monoatomic gas will be:
- BITSAT - 2024
- specific heat capacity
- If \( a, c, b \) are in GP, then the area of the triangle formed by the lines \( ax + by + c = 0 \) with the coordinate axes is equal to:
- BITSAT - 2024
- Vectors
Concepts Used:
Nuclear Physics
Nuclear physics is the field of physics that studies atomic nuclei and their constituents and interactions, in addition to the study of other forms of nuclear matter. Nuclear physics should not be confused with atomic physics, which studies the atom as a whole, including its electrons
Radius of Nucleus
‘R’ represents the radius of the nucleus. R = RoA1/3
Where,
- Ro is the proportionality constant
- A is the mass number of the element
Total Number of Protons and Neutrons in a Nucleus
The mass number (A), also known as the nucleon number, is the total number of neutrons and protons in a nucleus.
A = Z + N
Where, N is the neutron number, A is the mass number, Z is the proton number
Mass Defect
Mass defect is the difference between the sum of masses of the nucleons (neutrons + protons) constituting a nucleus and the rest mass of the nucleus and is given as:
Δm = Zmp + (A - Z) mn - M
Where Z = atomic number, A = mass number, mp = mass of 1 proton, mn = mass of 1 neutron and M = mass of nucleus.