A photon of energy 8 eV is incident on a metal surface of work...

According to Einstein's photoelectric equation, the maximum kinetic energy of the emitted photoelectrons is given by:

K_\max = E - \Phi

where $E$ is the energy of the incident photon and $\Phi$ is the work function of the metal.

Substituting the given values:

K_\max = 8 \text{ eV} - 3.75 \text{ eV} = 4.25 \text{ eV}

The stopping potential $V_0$ is related to the maximum kinetic energy by K_\max = e V_0.

Therefore, $e V_0 = 4.25 \text{ eV}$

$V_0 = 4.25 \text{ V}$

Answer: $4.25 \text{ V}$