Which of the following is NOT a characteristic of line spectra of atoms?

The Rydberg constant $R$ for hydrogen is

The wavelength of the first line of the Lyman series for hydrogen is approximately 121.6 nm. What is the wavelength of the second line?

The spectral series of the hydrogen spectrum that lies in the ultraviolet region is the

The absorption transitions between the first and the fourth energy states of hydrogen atom are ${\rm{3}}$. The emission transitions between these states will be

The first member of the Paschen series in hydrogen spectrum is of wavelength $18,800\,\,{A^0}$. The short wavelength limit of Paschen series is

If the wavelength of the first line of the Balmer series of hydrogen is $6561 \, \mathop {ext{A}}\limits^ \circ ,$ the wavelength of the second line of the series should be

Which of the following transitions will have highest emission wavelength

The wavelength of the energy emitted when electron comes from fourth orbit to second orbit in hydrogen is $20.397\,\,cm$. The wavelength of energy for the same transition in $H{e^ + }$ is

Work required to pull an electron from helium atom is 40 eV. Then the work required to pull both the electrons from the helium atom is

In an atom for the electron to revolve around the nucleus, the necessary centripetal force is obtained from the following force exerted by the nucleus on the electron