Photoelectrons are emitted from a photosensitive surface for light of wavelengths $\lambda_{1} = 360 \ nm$ and $\lambda_{2} = 600 \ nm$. What is the ratio of the work functions for the lights of wavelengths $\lambda_{1}$ and $\lambda_{2}$?

The stopping potential $V_0$ (in $volt$) as a function of frequency $(\nu)$ for a sodium emitter is shown in the figure. The work function of sodium,from the data plotted in the figure,will be: ................. $eV$
(Given: Planck's constant $(h) = 6.63 \times 10^{-34} \, Js$,electron charge $e = 1.6 \times 10^{-19} \, C$)

The figure represents a graph of the maximum kinetic energy $(K)$ of photoelectrons (in $eV$) versus the frequency $(\nu)$ of incident radiation for a metal used as a cathode in a photoelectric experiment. The work function of the metal is ............. $eV$.

The maximum velocity of emitted photoelectrons is $4.8 \ m/s$. If the $e/m$ ratio of an electron is $1.76 \times 10^{11} \ C/kg$,then the stopping potential is ......

$A$ copper ball of radius $1\, cm$ and work function $4.47\, eV$ is irradiated with ultraviolet radiation of wavelength $2500\, \mathring{A}$. The effect of irradiation results in the emission of electrons from the ball. Further,the ball will acquire charge,and due to this,there will be a finite value of the potential on the ball. The charge acquired by the ball is:

Let $K_1$ be the maximum kinetic energy of photoelectrons emitted by a light of wavelength $\lambda_1$ and $K_2$ corresponding to $\lambda_2$. If $\lambda_1 = 2\lambda_2$,then: