Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NEET 2026
Exam
NEET
Year
2026
Subject
Physics
Chapter
Nuclear Physics

NEET 2026 · Physics · Nuclear Physics

Consider the following nuclear reaction : ^ 238 Uarrow ^ 234 Th+...

Consider the following nuclear reaction :
238U→234Th+4He^{238}\text{U}\rightarrow{}^{234}\text{Th}+{}^4\text{He}
Take masses of 238U^{238}\text{U}, 234Th^{234}\text{Th} and 4He^4\text{He} as 238.050238.050 u, 234.043234.043 u and 4.0034.003 u, respectively. The Q value for the reaction, in keV, is :
[Given : 11 u =931.5=931.5 MeV c−2^{-2}]

Options

  1. A37403740
  2. B37263726
  3. C37303730
  4. D37363736

Correct answer

B. 37263726

Step-by-step solution

The mass defect Δm\Delta m for the given nuclear reaction is:

Δm=m(238U)−[m(234Th)+m(4He)]\Delta m = m(^{238}\text{U}) - [m(^{234}\text{Th}) + m(^4\text{He})]

Δm=238.050−(234.043+4.003)\Delta m = 238.050 - (234.043 + 4.003)

Δm=238.050−238.046=0.004 u\Delta m = 238.050 - 238.046 = 0.004 \text{ u}

The QQ value of the reaction is given by:

Q=Δm×931.5 MeVQ = \Delta m \times 931.5 \text{ MeV}

Q=0.004×931.5 MeVQ = 0.004 \times 931.5 \text{ MeV}

Q=3.726 MeVQ = 3.726 \text{ MeV}

Converting to keV:

Q=3.726×103 keV=3726 keVQ = 3.726 \times 10^3 \text{ keV} = 3726 \text{ keV}

Answer: 37263726
Practice Nuclear Physics on Quantrex Academy →

More from Nuclear Physics

Consider the following nuclear fission reaction _0^1 n + _ 92 ^ 235 U arrow _Z^A Y + _ 41… MHT CET Medical 2026Two spherical nuclei have mass numbers 216 and 64 with their radii R_1 and R_2… MHT CET Medical 2026At time t = 0 , the activity of a radioactive substance is 1600 Bq. At t= 8 s, the… MHT CET Medical 2026A radioactive nucleus _ 92 X^ 235 decays to _ 91 Y^ 231 . Which of the following… MHT CET Medical 2026In a given reaction, ^ A _ Z X arrow ^ A _ Z+1 Y arrow ^ A-4 _ Z-1 K arrow ^ A-4 _ Z-1 K… MHT CET Medical 2026When a nucleus in an atom undergoes a radioactive decay, the atomic number and/or mass… MHT CET Medical 2026A common example of β^- decay is _ 15 ^ 32 _ 16 ^ 32 + x + y Then x and y , respectively… MHT CET Medical 2026For a radioactive nucleus that undergoes β^+ decay, which of the following CANNOT occur? MHT CET Medical 2026 Full Nuclear Physics list All NEET PYQs