The $Cs^+$ ion imparts a violet color to the flame. How is this related to the emitted radiation?

The Vijayawada $FM$ radio station broadcasts at a frequency of $103.4 \ MHz$. The wavelength of the corresponding radio waves (in $m$) is

What is an emission spectrum?

The energy of one mole of photons of radiation of frequency $2 \times 10^{12} \ Hz$ in $J \ mol^{-1}$ is $.....$ (Nearest integer) (Given: $h = 6.626 \times 10^{-34} \ Js$,$N_A = 6.022 \times 10^{23} \ mol^{-1}$)

Splitting of spectral lines under the influence of a magnetic field is called:

$a$,$b$,$c$,$d$ are electromagnetic radiations. Frequencies of $a$,$b$ are $3 \times 10^{15} \ Hz$,$2 \times 10^{14} \ Hz$,respectively,whereas wavelengths of $c$,$d$ are $400 \ nm$,$750 \ nm$,respectively. The increasing order of their energies is