When light of frequency $v$ is incident on two metallic plates $A$ and $B$,photoelectrons are emitted. If the work function of $A$ is greater than that of $B$,which of the following curves correctly represents the relationship between the stopping potential $V$ and the incident frequency $v$?

The maximum kinetic energy of the photoelectrons varies:

$A$ photon of energy $3.4 \ eV$ is incident on a metal having work function $2 \ eV$. The maximum kinetic energy $(K.E.)$ of photo-electrons is equal to ........... $eV$. (in $eV$)

When light of frequency twice the threshold frequency is incident on a metal plate,the maximum velocity of the emitted electron is $v_{1}$. When the frequency of incident radiation is increased to five times the threshold value,the maximum velocity of the emitted electron becomes $v_{2}$. If $v_{2} = x v_{1}$,the value of $x$ will be...........

If the work function of $Na$ metal is $2.3 \ eV$,in which of the following regions of the $EM$ spectrum does the threshold wavelength lie?

$A$ Hydrogen-like atom has atomic number $Z$. Photons emitted in the electronic transitions from level $n=4$ to level $n=3$ in these atoms are used to perform a photoelectric effect experiment on a target metal. The maximum kinetic energy of the photoelectrons generated is $1.95 \ eV$. If the photoelectric threshold wavelength for the target metal is $310 \ nm$,the value of $Z$ is: