In photoelectric experiment energy of $2.48 \mathrm{eV}$ irradiates a photo sensitive material. The stopping…
In photoelectric experiment energy of $2.48 \mathrm{eV}$ irradiates a photo sensitive material. The stopping potential was measured to be $0.5 \mathrm{~V}$. Work function of the photo sensitive material is :
$1.68 \mathrm{eV}$
$2.48 \mathrm{eV}$
$1.98 \mathrm{eV}$
$0.5 \mathrm{eV}$
Solution
$\begin{aligned} & \mathrm{eV} \mathrm{V}_{\mathrm{s}}=\mathrm{h} \nu-\phi \\ & 0.5 \mathrm{~V}=2.48-\phi \\ & \text { work function }(\phi)=2.48 \mathrm{~V}-0.5 \mathrm{~V}=1.98 \mathrm{~V}\end{aligned}$