Physics

Nuclear and Atomic Physics

571 Questions

Nuclear and atomic physics explores the components and properties of the nucleus, including isotopes, radioactive decay, and fundamental forces. These concepts are essential for various competitive exams requiring a strong foundation in physics. The provided questions cover structural properties, mass, energy equivalence, and particle interactions.

Nucleus propertiesIsotopes and mass numberAlpha particle scatteringNuclear forcesMass energy equivalenceBeta particle emission

Nuclear and Atomic Physics Questions

Multiple choice physics nuclear physics beta decay change in nucleus due to radioactive decay alpha, beta and gamma particles (rays) and their properties

During a $\beta ^-$ decay which of the following statements are correct?

  1. The daughter nucleus has one proton less than the parent nucleus

  2. The daughter nucleus has one proton more than the parent nucleus

  3. An electron which is already present within the nucleus is rejected

  4. A neutron in the nucleus decays emitting an electron
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
$\beta ^- Decay$
$^\theta _{-1}e$ or $^o _{-1}\beta \rightarrow$ Symbols for Beta particles emitted during $\beta^-$ decay.
$\theta \rightarrow$ electron is emitted
Eg- $ _{ 53 }^{ 131 }{ I }\rightarrow _{ 54 }^{ 131 }{ Xe }+ _{ -1 }^{ 0 }{ \beta  }+\bar { { \upsilon  } _{ e } } $
where,  $ _{ -1 }^{ 0 }{ \beta  }$ is $\beta$ particle
$\bar { { \upsilon  } _{ e } }$ is antineutrino
So, $(B)$ is correct option.
Multiple choice physics nuclear physics beta decay change in nucleus due to radioactive decay alpha, beta and gamma particles (rays) and their properties

Masses of neutron, proton and electron are $1.0087$U, $1.0073$u and $0.0005$u respectively. If a neutron decays into a proton and an electron, the energy released would be about.

  1. $0.68$ MeV
  2. $0.84$ MeV
  3. $0.75$ MeV
  4. $1.22$ MeV
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

$^1 _0n\rightarrow$ $^1 _1p+$ $^0 _{-1}e$
$Q=(m _n=m _p-m _e)c^2$

$=0.0009\times 931.5$.
0.84

Multiple choice physics nuclear physics beta decay change in nucleus due to radioactive decay alpha, beta and gamma particles (rays) and their properties

During $\beta-decay$ (beta minus), the emission of antineutrino particle is supported by which of the following statement(s)?

  1. Angular momentum conservation holds good in any nuclear reaction.

  2. Linear momentum conservation holds good in any nuclear reaction.
  3. The KE of emitted $\beta-particle$ is varying continuously to a maximum value.

  4. None of the above.
Reveal answer Fill a bubble to check yourself
A,B,C Correct answer
Explanation

The following principles hold true in any situation in the universe
1. Conservation of linear momentum (if no external force)
2. Conservation of angular momentum (no external moment)
2. Conservation of energy
3. Conservation of charge

Multiple choice physics nuclear physics beta decay change in nucleus due to radioactive decay alpha, beta and gamma particles (rays) and their properties

A positron is emitted from $\mathrm{N}\mathrm{a} _{11}^{23}$. The ratio of the atomic mass and atomic number of the resulting nuclide is

  1. $22/10$
  2. $22/11$
  3. $23/10$
  4. $23/12$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When a positron is emitted from nucleus, proton will convert into a neutron. So atomic number will be decrease by one  but atomic mass will be constant. 

Thus, atomic mass / atomic number $=23/(11-1)=23/10 $

Multiple choice beta decay change in nucleus due to radioactive decay alpha, beta and gamma particles (rays) and their properties

A nucleus of magnesium decays into a nucleus of sodium by emitting a $\beta^{+}$ particle. The decay is
represented by the equation shown.
$^{23} _{12}Mg \rightarrow ^{P} _{Q}Na + ^{0} _{+1}\beta$
What are the values of $P$ and $Q$?

  1. $P = 22, Q = 11$
  2. $P = 22, Q = 13$
  3. $P = 23, Q = 11$
  4. $P = 23, Q = 13$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Since the no. of nucleons will conserved . 

So, comparing the no. of proton on both sides
$12 = Q+1$
$\implies Q = 11$
By conservation of mass 
$23 = P+0$
$\implies P = 23$

Multiple choice biology cell-the basic unit of life nucleus organelles in cell membranous and non-membranous organells

Nucleus is a

  1. Single layered structure

  2. Three layered structure

  3. Four layered structure

  4. Two layered structure
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The nucleus is two layered structure, it is a membrane-enclosed structure found in eukaryotic cells. It contains most of the cell's genetic material. The function of the nucleus is to maintain the integrity of the genes and to control the activities of the cell by regulating gene expression.

Multiple choice chemistry energy : forms and sources renewable and non-renewable resources renewable and non-renewable sources of energy production of electricity from solar energy

Atom bomb consists of pieces of $^{92}U _{235}$ and a source of

  1. Proton

  2. Neutron

  3. Meson

  4. Electron
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

An atomic bomb consists of two pieces of $ _{ 92 }{ U }^{ 235 }$ (or $ _{ 94 }{ Pu }^{ 219 }$) (plutonium) each smaller than the critical size and a source of neutrons

Multiple choice physics quantum physics photons concept of photon photons and photoelectric effect

Two free protons are separated by a distance of $1\mathring A $. If they are released the kinetic energy of proton when it infinite separation is

  1. $23 \times 10 ^ { 19 } j$
  2. $11.5 \times 10 ^ { - 19 } \mathrm { J }$
  3. $46 \times 10 ^ { - 19 } \mathrm { J }$
  4. $5.6 \times 10$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Potential energy U = k * q1 * q2 / r. U = 9e9 * (1.6e-19)^2 / 1e-10 = 23.04e-19 J. Since two protons share this energy, each gets half: 11.52e-19 J.

Multiple choice physics quantum physics photons concept of photon photons and photoelectric effect

Assume that a neutron breaks into a proton and an electron. The energy released suring this process is (mass of neutron $= 1.6725 \times 10^{-27} kg,$
mass od proton $= 1.6725 \times 10^{-27} kg,$ mass of electron$= 9 \times 10^{-31}kg)$

  1. 0.73 MeV

  2. 7.10 MeV

  3. 6.30 MeV

  4. 5.4 MeV
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

$\triangle m = (m _P + m _e) -m _n$

        $= 9 \times 10^{-31} kg $
 $(mc^2) \space energy \space released = (9 \times 10^{-31} kg) c^2 \space joules$
$= \dfrac{9 \times 10^{-31} \times (3 \times 10^8 )^2}{1.6 \times 10^{-13}} Mev$

$= 0.73 Mev$
Hence option (A) is correct

Multiple choice nuclear reactions nuclear structure nuclei atomic nuclei physics

A nucleus of mass number $A$ originally at rest emits $\alpha$- particle with speed $v$. The recoil speed of daughter nucleus is:

  1. $\cfrac{4v}{A-4}$
  2. $\cfrac{4v}{A+4}$
  3. $\cfrac{v}{A-4}$
  4. $\cfrac{v}{A+4}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

By conservation of momentum, the momentum of the alpha particle (mass 4, speed v) must equal the momentum of the daughter nucleus (mass A-4, speed V). Thus, 4v = (A-4)V, so V = 4v / (A-4).

Multiple choice nuclear reactions nuclear structure nuclei atomic nuclei physics

As the mass number increase, binding energy per nucleon,

  1. increases

  2. decreases

  3. remain same

  4. may increase or may decrease
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The binding energy per nucleon curve rises sharply for light nuclei, peaks around iron (mass number 56), and then gradually decreases for heavier nuclei.

Multiple choice nuclear reactions nuclear structure nuclei atomic nuclei physics

Per nucleon energy of $ _ { 3 } L ^ { 7 }$ and $2 ^ { \mathrm { H } e ^ { 4 } }$  nucleus is 5. 60  MeV and 7.06 MeV then in$ _ { 3 } \mathrm { L } ^ { 7 } + _ { 1 } \mathrm { P } ^ { 1 } \rightarrow 2 _ { 2 } \mathrm { He } ^ { 4 }$ energy released is:

  1. $29.6 \mathrm { MeV }$
  2. $2.4MeV$
  3. $8.4 \mathrm { MeV }$
  4. $17.3 \mathrm { MeV }$
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice nuclear reactions nuclear structure nuclei atomic nuclei physics

Mass defect of an atom refers to 

  1. inaccurate measurement of mass of neutrons

  2. mass annihilated to produce energy to bind the nucleons

  3. packing fraction

  4. difference in the number of neutrons and protons in the nucleus
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

$ Mc^{2} + (B.E) = (N _{mN} + Z _{mP})c^{2}$
where,
         $M _{c} =  $  total mass of nucleus.
         $N _{mN} =  $  total mass of neutrons
         $N _{mP}  =  $  total mass of protons

Multiple choice nuclear reactions nuclear structure nuclei atomic nuclei physics

In a fission process, nucleus A divides into two nuclei B and C, their binding energies being $\mathbf { E } _ { \mathbf { a } ^ { * } }$   $E _ { b }$  and $E _ { c }$ respectively. Ihen

  1. $\mathbf { E } _ { \mathrm { b } } + \mathrm { E } _ { \mathrm { c } } = \mathrm { E } _ { \mathrm { a } }$
  2. $\mathrm { E } _ { \mathrm { b } } + \mathrm { E } _ { \mathrm { c } } > \mathrm { E } _ { \mathrm { a } }$
  3. $\mathrm { E } _ { \mathrm { b } } + \mathrm { E } _ { \mathrm { e } } < \mathrm { E } _ { \mathrm { a } }$
  4. $\mathrm { E } _ { \mathrm { b } } \mathrm { E } _ { \mathrm { c } } = \mathrm { E } _ { \mathrm { a } }$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

$\begin{array}{l} { E _{ b } }+{ E _{ c } }>{ E _{ a } } \ \, \because some\, \, energy\, \, is\, \, goen\, \, in\, \, breaking\, \, nuclie\, \, of\, \, A \ Hence, \ option\, \, A\, \, is\, \, correct\, \, answer. \end{array}$