Consider \(3^{\text{rd}}\) orbit of \(He^{+}\) (Helium). Using a non-relativistic approach, the speed of the electron in this orbit will be: (given \(Z=2\) and \(h\) (Planck's constant)\(= 6.6\times10^{-34}~\text{J-s}\))
1. \(2.92\times 10^{6}~\text{m/s}\)
2. \(1.46\times 10^{6}~\text{m/s}\)
3. \(0.73\times 10^{6}~\text{m/s}\)
4. \(3.0\times 10^{8}~\text{m/s}\)
1. | \( n_1 = 6~\text{and}~n_2 = 2\) |
2. | \( n_1 = 8~\text{and}~ n_2 = 1\) |
3. | \( n_1 = 8~\text{and}~ n_2 = 2\) |
4. | \(n_1 = 4~\text{and}~n_2 = 2\) |
An electron of a stationary hydrogen atom passes from the fifth energy level to the ground level. The velocity that the atom acquired as a result of photon emission will be:
(\(m\) is the mass of hydrogen atom, \(R\) is Rydberg constant and \(h\) is Plank’s constant)
1. \(\frac{24m}{25hR}\)
2. \(\frac{25hR}{24m}\)
3. \(\frac{25m}{24hR}\)
4. \(\frac{24hR}{25m}\)
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. \(2.5\times10^{15}~\text{Hz}\)
An electron in the hydrogen atom jumps from the excited state n to the ground state. The wavelength so emitted illuminates a photosensitive material having a work function of 2.75 eV. If the stopping potential of the photoelectron is 10V, then the value of n is:
1. 2
2. 3
3. 4
4. 5
Out of the following which one is not possible energy for a photon to be emitted by hydrogen atom according to Bohr's atomic model?
1. 0.65 eV
2. 1.9 eV
3. 11.1 eV
4. 13.6 eV
The energy of a hydrogen atom in the ground state is \(-13.6\) eV. The energy of a \(\mathrm{He}^{+}\) ion in the first excited state will be:
1. \(-13.6\) eV
2. \(-27.2\) eV
3. \(-54.4\) eV
4. \(-6.8\) eV
The electrons in the hydrogen atom jump from the excited state (n = 3) to its ground state (n = 1) and the photons thus emitted irradiate a photosensitive material. If the work function of the material is 5.1 eV, the stopping potential is estimated to be (the energy of the electron in nth state ):
1. 12.1 V
2. 17.2 V
3. 7 V
4. 5.1 V
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. | \(n= 4~\text{to}~n=3~\text{states}\) |
1. 3.4 eV
2. 6.8 eV
3. 10.2 eV
4. zero