Monochromatic radiation emitted when electron on hydrogen atom jumps from first excited to the ground state irradiates a photosensitive material. The stopping potential is measured to be \(3.57~\text{V}\). The threshold frequency of the material is:
1. \(4\times10^{15}~\text{Hz}\)
2. \(5\times10^{15}~\text{Hz}\)
3. \(1.6\times10^{15}~\text{Hz}\)
4. \(2.5\times10^{15}~\text{Hz}\)

Subtopic:  Bohr's Model of Atom |
 63%
From NCERT
AIPMT - 2012
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The ionization energy of the electron in the hydrogen atom in its ground state is \(13.6~\text{eV}\). The atoms are excited to higher energy levels to emit radiations of \(6\) wavelengths. The maximum wavelength of emitted radiation corresponds to the transition between:
1. \(n= 3~\text{to}~n=2~\text{states}\)
2. \(n= 3~\text{to}~n=1~\text{states}\)
3. \(n= 2~\text{to}~n=1~\text{states}\)
4. \(n= 4~\text{to}~n=3~\text{states}\)
Subtopic:  Bohr's Model of Atom |
 62%
From NCERT
AIPMT - 2009
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If the nucleus \({}_{13}^{27}\mathrm{Al}\) has a nuclear radius of about \(3.6\) fermis, then \({}_{52}^{125}\mathrm{Te}\) would have its radius approximately as:
1. \(6.0\) Fermi
2. \(9.6\) Fermi
3. \(12.0\) Fermi
4. \(4.8\) Fermi

Subtopic:  Various Atomic Models |
 72%
From NCERT
AIPMT - 2007
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In a discharge tube ionization of enclosed gas is produced due to collisions between:

1. positive ions and neutral atoms/molecules

2. negative electrons and neutral atoms/molecules

3. photons and neutral atoms/molecules

4. neutral gas atoms/molecules

Subtopic:  X-Ray (OLD NCERT) |
 57%
From NCERT
AIPMT - 2006
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The radius of Germanium \((\mathrm{Ge})\) nuclide is measured to be twice the radius of \({}_{4}^{9}\mathrm{Be}.\) The number of nucleons in \(\mathrm{Ge}\) is:
1. \(73\)
2. \(74\)
3. \(75\)
4. \(72\)

Subtopic:  Various Atomic Models |
 63%
From NCERT
AIPMT - 2006
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The total energy of an electron in the orbit of an atom is \(-3.4~\text{eV}\). Its kinetic and potential energies are, respectively:
1. \(3.4~\text{eV},~3.4~\text{eV}\)
2. \(-3.4~\text{eV},~-3.4~\text{eV}\)
3. \(-3.4~\text{eV},~-6.8~\text{eV}\)
4. \(3.4~\text{eV},~-6.8~\text{eV}\)
Subtopic:  Bohr's Model of Atom |
 85%
From NCERT
NEET - 2019
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\(\alpha\text{-}\)particle consists of:
1. \(2\) protons only.
2. \(2\) protons and \(2\) neutrons only.
3. \(2\) electrons, \(2\) protons, and \(2\) neutrons.
4. \(2\) electrons and \(4\) protons only.
Subtopic:  Various Atomic Models |
 67%
From NCERT
NEET - 2019
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The ratio of the longest wavelengths corresponding to the Lyman and Balmer series in the hydrogen spectrum is:
1. \(\frac{3}{23}\) 2. \(\frac{7}{29}\)
3. \(\frac{9}{31}\) 4. \(\frac{5}{27}\)
Subtopic:  Spectral Series |
 88%
From NCERT
AIPMT - 2013
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When an \(\alpha\text-\)particle of mass \(m\) moving with velocity \(v\) bombards on a heavy nucleus of charge \(Ze\), its distance of closest approach from the nucleus depends on \(m\) as:
1. \(\frac{1}{\sqrt{m}}\)
2. \(\frac{1}{m^{2}}\)
3. \(m\)
4. \( \frac{1}{m}\)
Subtopic:  Various Atomic Models |
 74%
From NCERT
NEET - 2016
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The ratio of kinetic energy to the total energy of an electron in a Bohr orbit of the hydrogen atom is:
1. \(1:1\)
2. \(1:-1\)
3. \(2:-1\)
4. \(1:-2\)

Subtopic:  Bohr's Model of Atom |
 80%
From NCERT
NEET - 2018
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