Tag: physics

Questions Related to physics

The particle emitted in the nuclear reaction 
$ _{z}\textrm{X}^{A}$ = $ _{z+1}\textrm{Y}^{A}$ + ..... will be 

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

  1. $\alpha$ -particle

  2. $\beta^{-}$ -particle

  3. $\beta{+}$ -particle

  4. $Photon$

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Correct Option: B
Explanation:
In $\beta^{-}$ decay, there is a gain of one proton and an anti-neutrino is emitted from nucleus, hence atomic number is increased by 1 and weight remains same.

The nucleus of mass  $M +  \Delta m$  is at rest and decays into two daughter nuclei of equal mass  $\dfrac {  M  } { 2 }$  each. Speed of light is  $ c.$ The speed of daughter nuclei is

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

  1. $c \dfrac { \Delta m } { M + \Delta m }$

  2. $c \sqrt { \dfrac { 2 \Delta m } { M } }$

  3. $c \sqrt { \dfrac { \Delta m } { M } }$

  4. $c \sqrt { \dfrac { \Delta m } { M + \Delta m } }$

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Correct Option: B

The particle $X$ in the following nuclear reaction is  $ _{7}^{13}\textrm{N}$ $\longrightarrow $ $ _{6}^{13}\textrm{C}+$  $ _{1}^{0}\textrm{e}$ + $X$

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

  1. $P$

  2. $v$

  3. $e^{-}$

  4. $\alpha$

Show answer
Correct Option: B
Explanation:

The given reaction :      $^{13} _7N\rightarrow ^{13} _6C + ^0 _1e + ^A _Z X$

Conservation of mass number :      $13 = 13 + 0 +A$              $\implies A=0$
Conservation of atomic number :      $7 = 6 + 1 +Z$              $\implies Z=0$
Thus, the particle $X$ is neutrino i.e.  $\nu$

A radioactive material initially contains $10gm$ and after few days $3gm$ is left, then the emission rate of $\alpha$ or $\beta$ particle:-

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

  1. Will continue as usual

  2. Becomes $0.3$times

  3. Increases

  4. None of the above

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Correct Option: B

The ionization potential for second He electron is 

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

  1. 13.6 V

  2. 27.2 V

  3. 54.4 V

  4. 3.4 V

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Correct Option: C

Which word equation represents $\beta^+$ decay?

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

  1. Proton $\rightarrow$ neutron $+$ electron $+$ electron antineutrino

  2. Proton $\rightarrow$ neutron $+$ electron $+$ electron neutrino

  3. Proton $\rightarrow$ neutron $+$ positron $+$ electron antineutrino

  4. Proton $\rightarrow$ neutron $+$ positron $+$ electron neutrino

Show answer
Correct Option: D
Explanation:

 Positive beta decay $(β+\ \ \text{decay})$ also called the  positron emission. In this decay  a proton in the parent nucleus decays into a neutron that remains in the daughter nucleus, and the nucleus emits a neutrino and a positron, which is a positive particle like an ordinary electron in mass but of opposite charge. Thus, positive beta decay produces a daughter nucleus, the atomic number of which is one less than its parent and the mass number of which is the same.

The equation can be written as :

$p \rightarrow n+ e^+ + v _e$

A radioactive substance contains a number of identical nuclei that emit $\beta$- particles. Which property of these nuclei remains unaltered by emission?

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

  1. charge

  2. neutron number

  3. nucleon number

  4. proton number

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Correct Option: C
Explanation:

We know that in any $\beta -$ emission the mass number of the nucleus does not changes .

This implies that the nucleon number will remain same. 
So, option C is correct.

In $\beta^-$ decay, a

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

  1. neutron converts into a proton emitting antineutrino.

  2. neutron converts into a proton emitting neutrino.

  3. proton converts into a neutron emitting antineutrino.

  4. proton converts into a neutron emitting neutrino.

Show answer
Correct Option: A
Explanation:

The reaction of beta decay is shown as :

$n \rightarrow p + e^- + \bar{\nu} _e$               (antineutrino)

So, in a $\beta-$ decay, a neutron converts into a proton emitting antineutrino.

option (A) is correct.

The number of $\beta$-particles, if a radioactive element $ _{90}X^{238}$ decays into $ _{83}Y^{222}$ is :

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

  1. $4$

  2. $6$

  3. $2$

  4. $1$

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Correct Option: D

Which of the following nuclei is produced when a $ _{92}U^{238}$ nucleus undergoes a $(d, 2n)$ reaction followed by a beta decay?

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

  1. $ _{93}Np^{238}$

  2. $ _{94}Pu^{239}$

  3. $ _{94}Pu^{238}$

  4. $ _{92}U^{238}$

Show answer
Correct Option: C