Q.
The stopping potential for photoelectric emission from a metal surface is plotted along Y-axis and frequency $\nu$ of incident light along X-axis. A straight line is obtained as shown. Planck's constant is given by
NTA AbhyasNTA Abhyas 2022
Solution:
Einstein's photoelectric equation is
$V=\frac{hν}{e}-\frac{hν_{0}}{e}$
Here, the slope of the line $=\frac{h}{e}$
$\Rightarrow \, h=$ Planck's constant = slope $\times e$
Hence, Planck's constant is product of slope of the line and charge on the electron.
$V=\frac{hν}{e}-\frac{hν_{0}}{e}$
Here, the slope of the line $=\frac{h}{e}$
$\Rightarrow \, h=$ Planck's constant = slope $\times e$
Hence, Planck's constant is product of slope of the line and charge on the electron.