A hydrogen ion and a singly ionised helium atom are accelerated from rest through the same potential difference. The ratio of their final speeds is close to:
1. \(1:2\)
2. \(10:7\)
3. \(5:7\)
4. \(2:1\)

Subtopic:  Various Atomic Models |
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\(\sqrt {d_1}\)  and \(\sqrt {d_2}\) are the impact parameters corresponding to scattering angles \(60^{\circ}\) and \(90^{\circ}\) respectively, when an \(\alpha\) particle is approaching a gold nucleus. For \(d_1 = xd_2\), the value of \(x\) will be:
1. \(2\)
2. \(3\)
3. \(4\)
4. \(5\)
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The magnetic moment of an electron \((e)\) revolving in an orbit around nucleus with an orbital angular momentum \(\vec{L}\) is given by:
1. \(\vec\mu_{L}=\frac{{e \vec {L}}}{2{m}} \)
2. \(\vec\mu_{L}=-\frac{{e \vec {L}}}{2 {m}} \)
3. \(\vec\mu_{L}=-\frac{{e \vec {L}}}{{m}} \)
4. \(\vec {{\mu}_{L}}=\frac{2 {e \vec {L}}}{{m}}\)
Subtopic:  Various Atomic Models |
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Which of the following schematic graphs correctly represents the results of Rutherford’s gold foil experiment with \(\alpha\text-\)particles?
(Here, \(\theta\) is the scattering angle, and \(Y\) is the number of \(\alpha\text-\)particles detected. The plots are schematic and not to scale.)

1. 2.
3. 4.
Subtopic:  Various Atomic Models |
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Which level of the single ionized carbon has the same energy as the ground state energy of the hydrogen atom?
1. \(6\)
2. \(8\)
3. \(4\)
4. \(3\)
Subtopic:  Various Atomic Models |
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In an \(\alpha \text-\)particle \((m=6.72 \times 10^{-27} \mathrm{~kg} ) \) scattering experiment, the distance of closest approach of the \(\alpha \text-\)particle is \(4.5 \times 10^{-14}~ \text{m}. \) If the atomic number of the target nucleus is \(Z=80,\) what is the maximum speed of the \(\alpha \text-\)particle? \(\left (\dfrac{1}{4 \pi \epsilon_0}=9 \times 10^9 ~\text{N}\text{m}^2~ \text{C}^{-2} \right ) \)

1. \(443\times 10^5 \text{ m/s}\) 2. \(387\times 10^5 \text{ m/s}\)
3. \(156\times 10^5 \text{ m/s}\) 4. \(123\times 10^5 \text{ m/s}\)
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If an alpha particle with energy \(7.7~\text{MeV}\) is bombarded on a thin gold foil, the closest distance from nucleus it can reach is: (in m)
(Atomic number of gold = \(79\) and \(\dfrac{1}{4 \pi \varepsilon_0}=9 \times 10^9\) in SI units)
1. \(2.95 \times 10^{-14}\)
2. \(2.95 \times 10^{-16}\)
3. \(3.85 \times 10^{-16}\)
4. \(3.85 \times 10^{-14}\)
Subtopic:  Various Atomic Models |
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\(7.9 ~\text {MeV}\) \(\alpha\)-particle scatters from a target material of atomic number \(79.\) From the given data the estimated diameter of nuclei of the target material is (approximately):
\(\left[\frac{1}{4 \pi \epsilon_{o}}=9 \times 10^9 ~\text{Nm}^2 / \text{C}^2 \text { and electron charge }=1.6 \times 10^{-19} \text{C}\right]\)
1. \(5.76\times10^{-14}\) m
2. \(1.44\times10^{-13}\) m
3. \(2.88\times10^{-14}\) m
4. \(1.69\times10^{-12}\) m
Subtopic:  Various Atomic Models |
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In Rutherford's alpha-particle scattering experiment, only a few alpha particles rebound back because
\(\mathrm{A}.\) The size of gold nucleus is very small as compared to the size of gold atom.
\(\mathrm{B}.\) Alpha particle and gold nucleus have equal charge.
\(\mathrm{C}.\) The impact parameter is minimum for a few alpha particles.
\(\mathrm{D}.\) A few alpha particles have very high kinetic energy.
\(\mathrm{E}.\) Only a few alpha particles undergo head-on collision with the nuclei.
Choose the correct answer from the option given below:
1. \(\mathrm{A, B}\) Only
2. \(\mathrm{B, E}\) Only
3. \(\mathrm{C, D}\) Only
4. \(\mathrm{A, C,E}\) Only
Subtopic:  Various Atomic Models |
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