Question:
Given figure shows few data points in a photo electric effect experiment for a certain metal. The minimum energy for ejection of electron from its surfface is : (Plancks constant $\left.\mathrm{h}=6.62 \times 10^{-34} \mathrm{~J} . \mathrm{s}\right)$
Correct Option: 1
Solution:
Graph of $\mathrm{V}_{\mathrm{s}}$ and f given (B $5.5,0$ )
$\mathrm{h} v=\phi+\mathrm{eV}_{\mathrm{s}}$
at $\mathrm{B} \mathrm{V}_{\mathrm{s}}=0, \quad v=5.5$
$\Rightarrow \quad \mathrm{h} \times 5.5 \times 10^{14}=\phi$
$\phi=\frac{6.62 \times 10^{-34} \times 5.5 \times 10^{14}}{1.6 \times 10^{-19}} \mathrm{eV}=2.27 \mathrm{eV}$