The threshold wavelength of a metal surface is $5 \times 10^{-10} \, m$. When it is illuminated by light of wavelength $2 \times 10^{-10} \, m$,the stopping potential is $V_0$. What will be the stopping potential if the wavelength of the incident light is doubled?

The stopping potential for electrons emitted from a photosensitive surface illuminated by light of wavelength $491\, nm$ is $0.710\, V$. When the incident wavelength is changed to a new value,the stopping potential is $1.43\, V$. The new wavelength is ....... $nm.$

$A$ 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:

Light rays consisting of photons with energy $1.8 \ eV$ are incident on a metal surface with a work function of $1.2 \ eV$. What is the stopping potential required to stop the emitted electrons in $eV$?

When radiation of wavelength $\lambda$ is incident on a metallic surface,the stopping potential is $4.8 \ V$. If the same surface is illuminated with radiation of double the wavelength,then the stopping potential becomes $1.6 \ V$. Then the threshold wavelength for the surface is

$A$ material $A$ exhibits the photoelectric effect. Its work function is $2.5 \ eV$ and the threshold wavelength is $\lambda$. Another material $B$ has a work function of $5 \ eV$. Find the threshold wavelength required to produce the photoelectric effect in $B$.