The frequency of yellow light having wavelength $600 \ nm$ is

The wavelength range of the visible spectrum extends from violet $(400 \, nm)$ to red $(750 \, nm).$ Express these wavelengths in frequencies $(Hz).$ $(1 \, nm = 10^{-9} \, m)$

Linear spectrum (line spectrum) is a characteristic of which of the following?

Fill in the blanks:
$(i)$ If the orbits around the nucleus contract,the electron will spiral into the nucleus in $....$ seconds.
$(ii)$ Waves used in radio broadcasting have a frequency of $....$ $Hz$.
$(iii)$ The $SI$ unit of frequency is $....$.
$(iv)$ The number of waves present in unit length is called $....$.

Work functions of four metals $M_1, M_2, M_3$ and $M_4$ are $4.8, 4.3, 4.75$ and $3.75 \ eV$ respectively. The metals which do not show photoelectric effect when light of wavelength $310 \ nm$ falls on the metals are

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