Electrons are emitted with kinetic energy $T$ from a metal plate by an irradiation of light of intensity $J$ and frequency $v$. Then, which of the following will be true?

$A$ silver sphere of radius $1 \ cm$ and work function $4.7 \ eV$ is suspended from an insulating thread in free space. It is under continuous illumination of $200 \ nm$ wavelength light. As photoelectrons are emitted,the sphere gets charged and acquires a potential. The maximum number of photoelectrons emitted from the sphere is $A \times 10^Z$ (where $1 < A < 10$). The value of $Z$ is:

Cut-off potentials for a metal in the photoelectric effect for light of wavelengths $\lambda_1$,$\lambda_2$,and $\lambda_3$ are found to be $V_1$,$V_2$,and $V_3$ volts. If $V_1$,$V_2$,and $V_3$ are in Arithmetic Progression,then $\lambda_1$,$\lambda_2$,and $\lambda_3$ will be in:

$A$ beam of electromagnetic radiation of intensity $6.4 \times 10^{-5} \; W/cm^{2}$ is comprised of wavelength $\lambda = 310 \; nm$. It falls normally on a metal surface (work function $\varphi = 2 \; eV$) of surface area $1 \; cm^{2}$. If one in $10^{3}$ photons ejects an electron, the total number of electrons ejected in $1 \; s$ is $10^{x}$. Then $x$ is: $(hc = 1240 \; eV \cdot nm, 1 \; eV = 1.6 \times 10^{-19} \; J)$

The work function of a metal is $1.6 \times 10^{-19} \, J$. When the metal surface is illuminated by light of wavelength $6400 \, \mathring{A}$,the maximum kinetic energy of the emitted photo-electrons will be. (Planck's constant $h = 6.4 \times 10^{-34} \, Js$)

The ratio of work functions of two metals $A$ and $B$ is $1:2$. If radiations of frequencies $f$ and $2f$ are incident on the surfaces of $A$ and $B$ respectively,the ratio of the maximum kinetic energies of the emitted photoelectrons will be: (Given $f >$ threshold frequency of $A$ and $2f >$ threshold frequency of $B$)