Question

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. Planck’s constant is given by

• A. Slope of the line
• B. Product of slope on the line and charge on the electron
• C. Product of intercept along Y-axis and mass of the electron
• D. Product of Slope and mass of electron

Answer 1

Answer: (B)

$K_{\max }=hv-h{v}_0$
$\Rightarrow e{V}_0=hv-h{v}_0$
$\Rightarrow V_0=\frac{h}{e}v-\frac{h{v}_0}{e}$
Comparing this equation with $y=mx+c$,
we get slope $m=\frac{h}{e}$
$\Rightarrow h=m\times e$