Tag: nuclei

Quizzes (7) Questions (160)

Questions Related to nuclei

Multiple choice physics nuclei nuclear force the nuclear force nuclear force and binding energy

Two Nucleons are at a separation of $1$ fermi. Proton have a charge $1.6\times10^{-19}$ $C$, the nuclear force between them is $F _{1}$ both are neutrons, $F _{2}$ if both are protons, $F _{3}$ if one neutron and one proton then

  1. $F _{1}$ = $F _{2}$>$F _{3}$
  2. $F _{1}$ = $F _{2}$ = $F _{3}$
  3. $F _{1}$<$F _{2}$<$F _{3}$
  4. $F _{1}$ = $F _{2}$<$F _{3}$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Nuclear force is independent of charge of the nucleons.

Thus nuclear force is same for any pair of two nucleons which are at same distance apart.
$\therefore        F _1 = F _2 = F _3$

Multiple choice physics nuclei nuclear force the nuclear force nuclear force and binding energy

Two nucleons are at a separation of $1$ fermi. The net force between them is $F _{1}$, if both are neutrons, $F _{2}$ if both are protons and $F _{3}$, if one is a proton and the other is a neutron

  1. $F _{1} > F _{2} > F _{3}$
  2. $F _{2} > F _{1} > F _{3}$
  3. $F _{1} = F _{3} > F _{2}$
  4. $F _{1} = F _{2} > F _{3}$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Nuclear forces are the strongest forces in nature.
Nuclear forces are the strong forces of attraction which hold together the nucleons (neutrons and protons) in the tiny nucleus of an atom, inspite of strong electrostatic forces of repulsion between protons. Nuclear forces act between a pair of neutrons, a pair of protons and also between a neutron, proton pair with the same strength. This shows that nuclear forces are independent of charge.
The attractive nuclear force is the same for any pair of nucleons. Thus, $F _{1} = F _{3}$ when there are no electrostatic forces, but
$F _{2} =$ attractive nuclear force $-$ repulsive electrostatic force
Hence, $F _{1} = F _{3} > F _{2}$

Multiple choice physics nuclei nuclear force the nuclear force nuclear force and binding energy

Two nucleons are at a separation of one Fermi. Protons have a charge of $+1.6\times 10^{-19}$ C. The net nuclear force between them is $F _1$, if both are neutrons, $F _2$ if both are protons and $F _3$ if one is proton and the other is neutron. Then.

  1. $F _1 = F _2 >F _3$
  2. $F _1=F _2=F _3$
  3. $F _1< F _2 < F _3$
  4. $F _1 > F _2 > F _3$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Mass of proton = Mass of neutron = $1.67\times 10^{-27}Kg$
So, force between proton - proton, proton - neutron, neutron - neutron are equal.
So, $F _1=F _2=F _3$
Multiple choice physics nuclei nuclear force the nuclear force nuclear force and binding energy

A radioactive nucleus has specific binding energy '${E} _{1}$'. It emits an $\alpha$-particle. The resulting nucleus has specific binding energy '${E} _{2}$'. Then

  1. ${E} _{2}={E} _{1}$
  2. ${E} _{2}<{E} _{1}$
  3. ${E} _{2}>{E} _{1}$
  4. ${E} _{2}=0$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A radioactive nucleus always decays into more stable nucleus and high binding energy corresponds to more stable nucleus. Therefore, after emitting an alpha particle energy $E _2$ will be more than the initial energy $E _1$.

Multiple choice physics nuclei nuclear force the nuclear force nuclear force and binding energy

The nature of the electrostatic force and nuclear force between a proton and a neutron inside a nucleus are respectively.

  1. Repulsive and attractive

  2. Zero and attractive

  3. Repulsion and repulsive

  4. Attractive and attractive
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Since neutron is neutral in nature, the electrostatic force between neutron and proton is zero. They have attractive nuclear force between them which causes the nucleus to bind together. 

Multiple choice physics nuclei nuclear force the nuclear force nuclear force and binding energy

Range of nuclear force is approximately

  1. $2 \times 10^{-l5} m$
  2. $1.5 \times 10^{-20} m$
  3. $7.2 \times 10^{-4} m$
  4. $1.4 \times 10^{-15} m$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The nuclear force is powerfully attractive between nucleons at distance of about 1 femtometre or $1.0\times{10}^{-15}$ metre, but it rapidly decreases to insignificance at distance beyond about 2.5fm
So, $(A)$ is correct.
Multiple choice physics nuclei nuclear force the nuclear force nuclear force and binding energy

Which of the following statements is wrong

  1. Strong nuclear forces are the strongest forces

  2. Nuclear forces are very short range forces

  3. nuclear force increases when the number of nucleons is increased

  4. None of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
There are four fundamental interactions account for all observed forces. These interactions are strong nuclear, electromagnetic, weak nuclear and gravitational
The strongest of these four is the strong nuclear. It is responsible for binding together the fundamental particles of matter to form larger particles.
However this interaction operates at a very short range inside the nucleus (as little as $1$fm- $1$ femo meter or ${ 10 }^{ -15 }$ meter)
Nuclear force is defined as the force exerted between numbers of nucleons. So nuclear force increases when the number of nucleons is increased. All statements are correct.
Multiple choice physics nuclei nuclear force the nuclear force nuclear force and binding energy

The force between protons in the nucleus will b

  1. only nuclear

  2. only coulomb

  3. nuclear & coulomb

  4. coulomb & gravitational
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
The electrostatic force between an electron and a proton is given by Coulombs Law of force, that is directly proportional; to the product of charges of electron and the proton and inversely proportional to the square of distance between the two particles
Another force on proton is nuclear force as it the force exerted between numbers of nucleons. This force is attractive in nature which binds protons and neutrons in the nucleus together.
Multiple choice physics nuclei nuclear force the nuclear force nuclear force and binding energy

If the ionization energy of hydrogen atom is $13.6 eV$ then the wavelength of the radiation required to excite the electron in $L{ i }^{ ++ }$ from first to third Bohr orbit is approximately

  1. $1140 A$
  2. $914 A$
  3. $11.4 A$
  4. $134 A$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Ionisation energy is given by

$E = 13.6\ eV$ (given)
or $E = 13.6 \times 1.6 \times 10^{-19} J ....(1)$
also $E = hv$
$E = \dfrac{hc}{\lambda} ....(2)$
equation $(1)$ and $(2)$
$\dfrac{hc}{\lambda} = 13.6 \times 1.6 \times 10^{-19}$
$\lambda = \dfrac{h \times c}{13.6 \times 1.6 \times 10^{-19}}$
$\lambda = \dfrac{3 \times 10^{8} \times 6.63 \times 10^{-34}}{13.6 \times 1.6 \times 10^{-19}}$
$\lambda = 914 \times 10^{-10} m$
$\lambda = 914 A^o$