Select Question Set:
Q. No.The energy of an atom with a \(K\text-\)shell vacancy is \(E_K\), that with an \(L\text-\)shell vacancy is \(E_L\), and that with an \(M\text-\)shell vacancy is \(E_M\): all compared to an atom with no vacancy, then:
(I)
\(E_K<E_L\)
(II)
\(E_L>E_M\)
(III)
\(E_L -E_K=E_{K\alpha}\), the energy of \(K_\alpha \) photon
Choose the correct option from the options given below:
1.
(I) is true
2.
(I), (III) are true
3.
(II) is true
4.
(I), (II) are true
Subtopic: Bohr's Model of Atom |
Level 3: 35%-60%
Hints
Given below are two statements:
| Assertion (A): | When light consisting of wavelengths corresponding to the Balmer series is incident on a gas containing \(\mathrm{He}^{+}\) ions in the first three excited states - it can be absorbed by the \(\mathrm{He}^{+}\) ions. |
| Reason (R): | All the energy levels of the \(\mathrm{He}^{+}\) ions are the same as those of the \(\mathrm{H}\) atoms. |
| 1. | (A) is True but (R) is False. |
| 2. | (A) is False but (R) is True. |
| 3. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
| 4. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
Subtopic: Spectral Series |
64%
Level 2: 60%+
Hints
The zero of the potential energy is so chosen that the total energy of the hydrogen atom in its \(1^{st}\) excited state is zero. Then, the energy of the ground state of the hydrogen atom is:
| 1. | \(-3.4~\text{eV}\) | 2. | \(-6.8~\text{eV}\) |
| 3. | \(-10.2~\text{eV}\) | 4. | \(-13.6~\text{eV}\) |
Subtopic: Bohr's Model of Atom |
Level 3: 35%-60%
Hints
Which of the following has the same orbital radius as the Bohr radius?
| 1. | \(n=2\) state of \(\mathrm{He}^{+}\) \(\left(Z=2\right)\) ion |
| 2. | \(n=4\) state of \(\mathrm{He}^{+}\) \(\left(Z=2\right)\) ion |
| 3. | \(n=2\) state of \(\mathrm{Be}^{3+}\)\(\left(Z=4\right)\) ion |
| 4. | \(n=3\) state of \(\mathrm{Li}^{2+}\) \(\left(Z=3\right)\) ion |
Subtopic: Bohr's Model of Atom |
79%
Level 2: 60%+
Hints
In stimulated emission, an incoming photon interacts with an excited atom (e.g. \(\mathrm{H}^{*}\)) and brings the atom to its ground state, while an extra photon is emitted - as it happens in a laser. When a photon stimulates the emission of another photon, the two photons have:
| 1. | the same phase. |
| 2. | the same energy. |
| 3. | the same direction. |
| 4. | the same phase, energy, and direction. |
Subtopic: Spectral Series |
52%
Level 3: 35%-60%
Hints
Whenever a photon is emitted by a hydrogen atom in the Paschen series, it is followed by further emissions of photons, in the Balmer series or the Lyman series.
These photons can have:
These photons can have:
| 1. | 2 possible energy values. |
| 2. | 3 possible energy values. |
| 3. | 4 possible energy values. |
| 4. | 5 possible energy values. |
Subtopic: Spectral Series |
65%
Level 2: 60%+
Hints
Given below are two statements:
| Assertion (A): | The magnetic moment of a hydrogen-like atom is higher when it is in a state of higher quantum number \(n.\) |
| Reason (R): | The magnetic moment of hydrogen-like atom, as calculated from Bohr's theory, is directly proportional to the principal quantum number \(n.\) |
| 1. | (A) is True but (R) is False. |
| 2. | (A) is False but (R) is True. |
| 3. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
| 4. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
Subtopic: Bohr's Model of Atom |
77%
Level 2: 60%+
Hints
An electron of mass \(m\) (charge \(e\)) moves in a circular orbit in a uniform magnetic field. Assume that Bohr's law of quantisation of angular momentum is valid for the electron. The minimum possible magnetic flux (flux of magnetic field) through the electron's orbit is:
| 1. | \(\dfrac he\) | 2. | \(\dfrac h{2e}\) |
| 3. | \(\dfrac {2h}e\) | 4. | \(\dfrac h{2\pi e}\) |
Subtopic: Bohr's Model of Atom |
56%
Level 3: 35%-60%
Hints
Electrons accelerated through a potential difference \(V_0\) are incident on a gas of hydrogen atoms in the ground state. For what minimum value of \(V_0\) will the collisions of the electrons with the atom be perfectly inelastic?
1. \(13.6\) V
2. \(27.2\) V
3. \(10.2\) V
4. \(6.8\) V
1. \(13.6\) V
2. \(27.2\) V
3. \(10.2\) V
4. \(6.8\) V
Subtopic: Bohr's Model of Atom |
Level 4: Below 35%
Hints
An electron in an \(\mathrm{H}\text-\)atom makes a transition from the ground state into another state where its de-Broglie wavelength is doubled. The energy required to make this transition is:
1. \(13.6~\text{eV}\)
2. \(10.2~\text{eV}\)
3. \(12.75~\text{eV}\)
4. \(12.1~\text{eV}\)
1. \(13.6~\text{eV}\)
2. \(10.2~\text{eV}\)
3. \(12.75~\text{eV}\)
4. \(12.1~\text{eV}\)
Subtopic: Bohr's Model of Atom |
71%
Level 2: 60%+
Hints
Select Question Set:
© 2025 GoodEd Technologies Pvt. Ltd.