NEET Nuclei PYQ practice sheet

13 previous-year NEET Physics questions from Nuclei, newest papers first. Nuclei carries 13 of the Physics questions in NEET 2020 to 2026, so this is a good place to test yourself after revising the chapter. Marking: +4 correct, −1 wrong.

1. 1.

   RE-NEET 2026

   Consider the following nuclear reaction $^{238}\mathrm{U} \longrightarrow\, ^{234}\mathrm{Th} + \,^{4}\mathrm{He}$ Take masses of $^{238}$U, $^{234}$Th and $^{4}$He as 238.050 u, 234.043 u and 4.003 u, respectively. The $Q$ value for the reaction, in keV, is: [Given: $1\ \mathrm{u} = 931.5\ \mathrm{MeV\,c^{-2}}$]

   • (A)
     $3736$
   • (B)
     $3726$
   • (C)
     $3730$
   • (D)
     $3740$
2. 2.

   NEET 2026

   Four statements are given (A is mass number): A. The volume of a nucleus is proportional to $A^{1/3}$. B. The volume of a nucleus is proportional to $A$. C. The difference in mass of an atom and its nucleus is called the mass defect. D. The difference in mass of a nucleus and its constituents is called the mass defect. Choose the correct answer from the options given below:

   • (A)
     A and C are true, but B and D are false
   • (B)
     A and D are true, but B and C are false
   • (C)
     B and D are true, but A and C are false
   • (D)
     B and C are true, but A and D are false
3. 3.

   NEET 2026

   An unknown nucleus has a nuclear density of $2.29\times10^{17}\ \text{kg m}^{-3}$ and mass of $19.926\times10^{-27}$ kg. Its mass number $A$ is approximately: (Take $R_0=1.2\times10^{-15}$ m, $4\pi=12.56$)

   • (A)
     16
   • (B)
     20
   • (C)
     19
   • (D)
     12
4. 4.

   NEET 2024

   $^{290}_{82}X \xrightarrow{\alpha} Y \xrightarrow{e^{+}} Z \xrightarrow{\beta^{-}} P \xrightarrow{e^{-}} Q$ In the nuclear emission stated above, the mass number and atomic number of the product $Q$ respectively, are:

   • (A)
     286, 80
   • (B)
     286, 81
   • (C)
     280, 81
   • (D)
     288, 82
5. 5.

   NEET 2023

   The half life of a radioactive substance is $20$ minutes. In how much time, the activity of substance drops to $\left(\dfrac{1}{16}\right)^{th}$ of its initial value?

   • (A)
     80 minutes
   • (B)
     20 minutes
   • (C)
     40 minutes
   • (D)
     60 minutes
6. 6.

   NEET 2022

   In the given nuclear reaction, the element X is:

   $$^{22}_{11}\mathrm{Na}\rightarrow X + e^{+}+\nu$$

   • (A)
     $^{22}_{12}\mathrm{Mg}$
   • (B)
     $^{23}_{11}\mathrm{Na}$
   • (C)
     $^{23}_{10}\mathrm{Ne}$
   • (D)
     $^{22}_{10}\mathrm{Ne}$
7. 7.

   NEET 2022

   A nucleus of mass number 189 splits into two nuclei having mass number 125 and 64. The ratio of radius of the two daughter nuclei, respectively, is:

   • (A)
     25 : 16
   • (B)
     1 : 1
   • (C)
     4 : 5
   • (D)
     5 : 4
8. 8.

   NEET 2021

   A radioactive nucleus $^{A}_{Z}\mathrm{X}$ undergoes spontaneous decay in the sequence $^{A}_{Z}\mathrm{X} \rightarrow {}_{Z-1}\mathrm{B} \rightarrow {}_{Z-3}\mathrm{C} \rightarrow {}_{Z-2}\mathrm{D}$, where $Z$ is the atomic number of element X. The possible decay particles in the sequence are :

   • (A)
     $\alpha, \beta^{-}, \beta^{+}$
   • (B)
     $\alpha, \beta^{+}, \beta^{-}$
   • (C)
     $\beta^{+}, \alpha, \beta^{-}$
   • (D)
     $\beta^{-}, \alpha, \beta^{+}$
9. 9.

   NEET 2021

   A nucleus with mass number $240$ breaks into two fragments each of mass number $120$, the binding energy per nucleon of unfragmented nuclei is $7.6\ \mathrm{MeV}$ while that of fragments is $8.5\ \mathrm{MeV}$. The total gain in the Binding Energy in the process is :

   • (A)
     $804\ \mathrm{MeV}$
   • (B)
     $9.4\ \mathrm{MeV}$
   • (C)
     $216\ \mathrm{MeV}$
   • (D)
     $0.9\ \mathrm{MeV}$
10. 10.

    NEET 2021

    The half-life of a radioactive nuclide is $100$ hours. The fraction of original activity that will remain after $150$ hours would be :

    • (A)
      $\dfrac{2}{3\sqrt{2}}$
    • (B)
      $\dfrac{1}{2\sqrt{2}}$
    • (C)
      $\dfrac{2}{3}$
    • (D)
      $\dfrac{1}{2}$
11. 11.

    NEET 2020

    The energy required to break one bond in DNA is $10^{-20}$ J. This value in eV is nearly :

    • (A)
      6
    • (B)
      0.6
    • (C)
      0.06
    • (D)
      0.006
12. 12.

    NEET 2020

    The energy equivalent of $0.5$ g of a substance is :

    • (A)
      $4.5\times10^{16}$ J
    • (B)
      $4.5\times10^{13}$ J
    • (C)
      $1.5\times10^{13}$ J
    • (D)
      $0.5\times10^{13}$ J
13. 13.

    NEET 2020

    When a uranium isotope $^{235}_{92}\mathrm{U}$ is bombarded with a neutron, it generates $^{89}_{36}\mathrm{Kr}$, three neutrons and :

    • (A)
      $^{144}_{56}\mathrm{Ba}$
    • (B)
      $^{91}_{40}\mathrm{Zr}$
    • (C)
      $^{101}_{36}\mathrm{Kr}$
    • (D)
      $^{103}_{36}\mathrm{Kr}$