The work function of a photosensitive material is $4.0 \ eV$. The longest wavelength of light that can cause photon emission from the substance is approximately $...... \ nm$.

If the light from the Balmer series of hydrogen is used to eject photoelectrons from a metal, then the maximum work function of the metal can be: (in $\text{ eV}$)

In a photoelectric emission experiment,the stopping potential for a given metal is $V$ volt,when radiation of wavelength $\lambda$ is used. If radiation of wavelength $2 \lambda$ is used with the same metal,then the stopping potential (in volt) will be. [Given: $c = \text{velocity of light}$,$e = \text{charge on electron}$,$h = \text{Planck's constant}$]

In the photoelectric effect, the kinetic energy of the electron emitted from the metal surface depends upon:

The photoelectric work function for a metal surface is $4.125 \ eV$. The cut-off wavelength for this surface is .......... $\mathring{A}$.

The variation of stopping potential $(V_0)$ as a function of the frequency $\nu \ (\times 10^{14} \ Hz)$ of the incident light for a metal is shown in the figure. The work function of the surface is $........... \ eV$.