Atoms Test - 27...

The velocity of a helium nucleus travelling in a curved path in a magnetic field is $$V$$. The velocity of a proton moving in the same curved path in the same magnetic field is :

There are only three hydrogen atoms in a discharge tube. The analysis of spectrum shows that in all the hydrogen atoms, electrons are de-exciting from the fourth orbit. What should be the maximum number of spectral lines?

Rydberg atoms are the hydrogen atoms in higher excited states such atoms are observed in space.The orbit number for such an atom with radius about $$0.01\ mm$$ should be :

In one revolution round the hydrogen nucleus, an electron makes five crests .The electron belongs to

The threshold wavelength for a surface having a threshold frequency of $$0.6\times 10^{15}$$ Hz in ($$\mathring A$$) is

The ratio of momenta of an electron and a $$\alpha$$ -particle which is accelerated from rest by a potential difference of $$100 V$$ is:

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 ?

An electron of hydrogen atom is revolving in third Bohr's orbit $$(n=3)$$. The number of revolutions it will undergo before making a transition to the second orbit $$(n=2)$$ is
(Assume the average life time of an excited state of the hydrogen atom is in the order of $$10^{-8}s$$ and Bohr radius $$=5.3 \times 10^{-12} m$$)

The time taken by a photo-electron to come out after the photon strikes is approximately

If $$n_{r}$$ and $$n_{b}$$ are the number of photons of red and blue lights respectively with same energy, then