$A$ particular radio station broadcasts at a frequency of $1120 \, kHz$. Another radio station broadcasts at a frequency of $98.7 \, MHz$. What will be the wavelength of the radiation for each station?

How is an electron observed? Explain.

$\alpha$-rays have

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.

The number of incorrect statement/s about the black body from the following is $........$.
$(A)$ Emit or absorb energy in the form of electromagnetic radiation
$(B)$ Frequency distribution of the emitted radiation depends on temperature
$(C)$ At a given temperature,intensity vs frequency curve passes through a maximum value
$(D)$ The maximum of the intensity vs frequency curve is at a higher frequency at higher temperature compared to that at lower temperature

Find the mass of a photon emitted by a sodium lamp (wavelength $\lambda = 5890 \ \mathring{A}$). How many times is this mass compared to the mass of an electron?