In a photoelectric effect experiment,if the frequency of light is doubled,the stopping potential will

Two light beams of different frequencies,having energies $1 \ eV$ and $2.5 \ eV$ respectively,are incident on a metal surface with a work function of $0.5 \ eV$. The ratio of the maximum kinetic energies of the emitted photoelectrons is:

When photons are incident on a photosensitive material of work function $1.5 \text{ eV}$,the maximum velocity of the emitted photoelectrons is $8 \times 10^5 \text{ m/s}$. The stopping potential of the photoelectrons is (Mass of the electron $= 9 \times 10^{-31} \text{ kg}$ and charge of the electron $= 1.6 \times 10^{-19} \text{ C}$) (in $V$)

When the wavelength of incident radiation is changed from $400 \ nm$ to $310 \ nm$,the maximum kinetic energy of the emitted photoelectrons is doubled. The work function of the metal is ........ $eV$.

Photons of energy $10 eV$ are incident on a photosensitive surface of threshold frequency $2 \times 10^{15} Hz$. The kinetic energy in $eV$ of the photoelectrons emitted is [Planck's constant $h = 6.63 \times 10^{-34} Js$]. (in $eV$)

If the wavelength of incident light is decreased from $4000 \ \mathring{A}$ to $3600 \ \mathring{A}$,then the change in stopping potential will be ............. $V$.