Kumar Mittal Solutions for Exercise 2: For DIFFERENT COMPETITIVE EXAMINATIONS

If the series limit frequency of the Lyman series is ${\nu }_L$, then the series limit frequency of the Pfund series is :

The wavelength of the first line of Lyman series for hydrogen atom is equal to that of the second line of Balmer series for a hydrogen like ion. The atomic number $Z$ of hydrogen like ion is

In the spectrum of hydrogen, the ratio of the longest wavelength in the Lyman series to the longest wavelength in the Balmer series is: 

An electron in the hydrogen atom jumps from excited state $\mathrm{n}$ to the ground state. The wavelength so emitted illuminates a photosensitive material having work function $2.75 \mathrm{eV}$. If the stopping potential of the photoelectron is $10 \mathrm{V}$, then the value of $\mathrm{n}$ is

An electron from various excited states of hydrogen atom emit radiation to come to the ground state. Let ${\lambda }_{n,}{\lambda }_g$  be the de Broglie wavelength of the electron in the ${\mathrm{n}}^{\mathrm{th}}$ state and the ground state respectively. Let  ${\wedge }_n$ be the wavelength of the emitted photon in the transition from the ${\mathrm{n}}^{\mathrm{th}}$state to the ground state. For large n, ($\mathrm{A},\mathrm{B}$are constants).

The total energy of an electron in an atom in it's orbit is $3.4 \mathrm{eV}$. Its kinetic and potential energies respectively are:

A  ${\mathrm{He}}^{+}$ ion is in its first excited state. Its ionization energy is?
 

In ${\mathrm{Li}}^{++}$, an electron in the first Bohr orbit is excited to a level by radiation of wavelength $\lambda$. when the ion gets de-excited to the ground state in all possible ways (including intermediate emissions), a total of six spectral lines are observed. What is the value of $\lambda$ ?
(Given :$\mathrm{h}=6.63\times {10}^{34} \mathrm{J} \mathrm{s}; \mathrm{c}=3\times {10}^8 \mathrm{m} {\mathrm{s}}^{-1}$)