The photoelectric effect can be caused by which of the following?

Yellow light emitted from a sodium lamp has a wavelength $(\lambda)$ of $580 \,nm$. Calculate the frequency $(v)$ and wave number $(\bar{v})$ of the yellow light.

Identify the region of the electromagnetic spectrum for the spectral lines when electron transition takes place from higher energy levels to $n=3, 4, 5$ in the atomic spectrum of hydrogen.

Two radiations having energies $E_1$ and $E_2$ as $15 \ eV$ and $45 \ eV$ respectively,then the relationship between $\lambda_1$ and $\lambda_2$ will be:

The ratio of the energy of a photon with wavelength $3000 \ \mathring{A}$ to that of a photon with wavelength $6000 \ \mathring{A}$ is:

What is the frequency of violet light having wavelength $400 \ nm$?