In hydrogen and hydrogen-like atoms,the ratio of the difference of energies $E_{4n}-E_{2n}$ and $E_{2n}-E_{n}$ varies with its atomic number $Z$ and $n$ as:

The first excited state of a hydrogen atom is $10.2 \, eV$ above its ground state. The temperature needed to excite hydrogen atoms to the first excited level is

The minimum energy required to excite a hydrogen atom from its ground state is.....$ eV$.

During the transition of an electron from state $A$ to state $C$ of a Bohr atom,the wavelength of the emitted radiation is $2000 \ \mathring A$ and it becomes $6000 \ \mathring A$ when the electron jumps from state $B$ to state $C.$ Then the wavelength of the radiation emitted during the transition of electrons from state $A$ to state $B$ is

The ionisation potential of hydrogen atom is $13.6 \ V$. The energy required to remove an electron from the second orbit of hydrogen is......$eV$.

The ratio of energies of photons produced due to the transition of an electron in a hydrogen atom from its $(i)$ second to first energy level and (ii) highest energy level to second energy level is: (in $3:1$)