Embibe Experts Solutions for Chapter: Structure of Atom, Exercise 3: Level 3

In Bohr series of lines of hydrogen spectrum, the third line from the red-end corresponds to which one of the following inter-orbit jumps of the electron for Bohr orbits in an atom of hydrogen?

A certain metal when irradiated by light $\left(\mathrm{\nu }=3.2\times {10}^{16} \mathrm{Hz}\right)$ emits photoelectrons with twice kinetic energy as did photoelectrons when the same metal is irradiated by light $\left(\mathrm{\nu }=2.0\times {10}^{16} \mathrm{Hz}\right)$. The ${\mathrm{\nu }}_0$ of metal is

The frequency of radiation emitted when electron falls from $\mathrm{n}=4$ to $\mathrm{n}=1$ in a hydrogen atom will be

(Given: Ionization energy of $\mathrm{H}=2.18\times {10}^{-18} \mathrm{J} {\mathrm{atom}}^{-1}$ and $\mathrm{h}=6.625\times {10}^{-34} \mathrm{J} \mathrm{s}$)

A metal is irradiated with a light of wavelength $660 \mathrm{nm}$. Given that the work function of the metal is $1.0 \mathrm{eV}$, the de-Broglie wavelength of the ejected electron is close to

A bulb of $40 \mathrm{W}$ is producing a light of wavelength $620 \mathrm{nm}$ with $80 \%$ of efficiency, then the number of photons emitted by the bulb in $20$ seconds are: $\left(1 \mathrm{eV}=1.6\times {10}^{-19} \mathrm{J}, \mathrm{hc}=12400 \mathrm{eV} \mathrm{\AA })\right.$

A plot of the kinetic energy $\left(\raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$2 $}\right.{\mathrm{mv}}^2\right)$ of ejected electrons as a function of the frequency $\left(\mathrm{v}\right)$ of incident radiation for four alkali metals $\left({\mathrm{M}}_1, {\mathrm{M}}_2, {\mathrm{M}}_3, {\mathrm{M}}_4\right)$ is shown below:

The alkali metals ${\mathrm{M}}_1, {\mathrm{M}}_2, {\mathrm{M}}_3$ and ${\mathrm{M}}_4$ are, respectively:

The photoelectric behaviour of $\mathrm{K}, \mathrm{Li}, \mathrm{Mg}$ and $\mathrm{Ag}$ metals is shown in the plot below. If light of wavelength $400 \mathrm{nm}$ is incident on each of these metals, which of them will emit photoelectrons? [Planck's constant $\mathrm{h}=6.626\times {10}^{-34} \mathrm{Js}$ and $1 \mathrm{eV}=1.6\times {10}^{-19} \mathrm{J}$]

The correct representation of wavelength intensity relationship of an ideal blackbody radiation at two different temperatures ${\mathrm{T}}_1$ and ${\mathrm{T}}_2$ is"