Search any question & find its solution
Question:
Answered & Verified by Expert
The light rays having photons of energy $4.2 \mathrm{eV}$ are falling on a metal surface having a work function of $2.2 \mathrm{eV}$. The stopping potential of the surface is:
Options:
Solution:
2742 Upvotes
Verified Answer
The correct answer is:
$2 \mathrm{~V}$
By Einstein photoelectric equation, we have;
$\begin{aligned}
\text { K.E. } & =h v-\phi \\
e \mathrm{~V}_0 & =4.2 \mathrm{eV}-2.2 \mathrm{eV} \\
e \mathrm{~V}_0 & =2 \mathrm{eV}=2 \text { volt }
\end{aligned}$
$\begin{aligned}
\text { K.E. } & =h v-\phi \\
e \mathrm{~V}_0 & =4.2 \mathrm{eV}-2.2 \mathrm{eV} \\
e \mathrm{~V}_0 & =2 \mathrm{eV}=2 \text { volt }
\end{aligned}$
Looking for more such questions to practice?
Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.