If the work function of the photoelectric surface is 3.3 eV, then the value of threshold frequency is:

$8×10^{14}Hz$ $5×10^{16}Hz$ $4×10^{11}Hz$ $8×10^{10}Hz$

$8×10^{14}Hz$

Here, $\phi_0=3.3eV=3.3×1.6×10^{-19}J$ Work function, $\phi_0=hv_0$ Where $v_0$ is the threshold frequency $v_0=\frac{\phi_0}{h}=\frac{3.3×1.6×10^{-19}J}{6.6×10^{-34}Js}=0.8×10^{15}Hz=8×10^{14}Hz$