The ionisation potential of hydrogen atom is

1. 13.60 volt

2. 8.24 volt

3. 10.36 volt 

4. 14.24 bolt

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. \(\frac{4n^2h^2}{4\pi^2m^2r^3}\)

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

Ionisation potential of hydrogen atom is 13.6 eV. Hydrogen atoms in the ground state are excited by monochromatic radiation of photon energy 12.1 eV. According to Bohr's theory, the spectral lines emitted by hydrogen will be:

1. two 

2. three

3. four 

4. one

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:

What happens whenever a hydrogen atom emits a photon in the Balmer series?

An $\alpha -$particle of energy 5 MeV is scattered through $180°$ by a fixed uranium nucleus. The distance of closest approach is of the order

1. ${10}^{-10}<mspace\; width="1em"></mspace>m$ 

2. ${10}^{-13}<mspace\; width="1em"></mspace>m$ 

3. ${10}^{-14}<mspace\; width="1em"></mspace>m$ 

4. ${10}^{-16}<mspace\; width="1em"></mspace>m$

Which source is associated with a line emission spectrum? 

1. Electric fibre 

2. Neon street Sign

3. Red traffic light 

4. Sun