The stopping potential V for photoelectric emission from a metal surface is plotted along Y-axis and frequency v of incident light along X-axis. A straight line is obtained as shown in the figure. Planck’s constant is given by:
Answer & explanation
Correct answer: option 2
According to Einstein’s photoelectric equation
$K=eV=hv-W_0$ or $V=\frac{h}{e}v-\frac{W_0}{e}$
∴ Slope of straight line between V and v is $\frac{h}{e}$.
∴ h = e × slope of straight line.