Q. No.According to Bohr's theory, the moment of momentum of an electron revolving in second orbit of hydrogen atom will be:
1. \(2\pi h\)
2. \(\pi h\)
3. \(\frac{h}{\pi}\)
4. \(\frac{2h}{\pi}\)
(\(h = 6.626\times 10^{-34}\) J-s)
1. \(1.11\times 10^{34}~\text{J-s}\)
2. \(1.51\times 10^{-31}~\text{J-s}\)
3. \(2.11\times 10^{-34}~\text{J-s}\)
4. \(3.72\times 10^{-34}~\text{J-s}\)
1. \(3.40~\text{eV}\)
2. \(1.51~\text{eV}\)
3. \(0.85~\text{eV}\)
4. \(0.66~\text{eV}\)
As per the Bohr model, the minimum energy (in eV) required to remove the electron from the ground state of a double ionised lithium ion (\(Z=3\)) is:
1. \(1.51\)
2. \(13.6\)
3. \(40.8\)
4. \(122.4\)
Orbital acceleration of electrons is:
1. \(\frac{n^2h^2}{4\pi^2m^2r^3}\)
2. \(\frac{n^2h^2}{4n^2r^3}\)
3. \(\frac{4n^2h^2}{\pi^2m^2r^3}\)
4. \(\frac{4n^2h^2}{4\pi^2m^2r^3}\)
1. \(\frac{n^2h^2}{4\pi^2m^2r^3}\)
2. \(\frac{n^2h^2}{4n^2r^3}\)
3. \(\frac{4n^2h^2}{\pi^2m^2r^3}\)
4. \(\frac{4n^2h^2}{4\pi^2m^2r^3}\)
The ratio of the energies of the hydrogen atom in its first to second excited states is
1.
2.
3.
4. 4
Out of the following which one is not a possible energy for a photon to be emitted by hydrogen atom according to Bohr's atomic model:
1. 13.6 eV
2. 0.65 eV
3. 1.9 eV
4. 11.1 eV
Consider the spectral line resulting from transition \(n=2\) to \(n = 1\) in the atoms and ions given below. The shortest wavelength is given by:
| 1. | hydrogen atom |
| 2. | deuterium |
| 3. | singly ionised helium |
| 4. | doubly ionised lithium |
The wavelength of Ka X-rays produced by an X-ray tube is 0.76 . Find the atomic number of the anode material of the tube?
1. 41
2. 30
3. 20
4. 10
An particle of energy 5 MeV is scattered through by a fixed uranium nucleus. The distance of closest approach is of the order
1.
2.
3.
4.
© 2025 GoodEd Technologies Pvt. Ltd.