When $\beta$-particles are sent through a tin metal foil,most of them go straight through the foil as

Which energy level transition among the following will have the least wavelength?

The work functions of two metals ($M_A$ and $M_B$) are in the $1:2$ ratio. When these metals are exposed to photons of energy $6 \ eV$, the kinetic energy of liberated electrons of $M_A:M_B$ is in the ratio of $2.642:1$. The work functions (in $eV$) of $M_A$ and $M_B$ are respectively.

In which transition is one quantum of energy emitted?

In the hydrogen spectrum,if an electron transitions from the $6^{th}$ orbit to the $3^{rd}$ orbit through multiple steps,what is the total number of spectral lines in the $U.V.$ region?

The ratio of the maximum wavelengths of the Lyman and Balmer series is ....