Q. The stopping potential $V$ for photoelectric emission for 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 of the line and charge on the electron
C) Intercept along $Y$-axis divided by charge on the electron
D) Product of intercept along $X$-axis and mass of the electron
Explanation
(b) $E_{k} = eV = hv - \phi_{0}$
or $V = \frac{h}{e}\ v - \frac{\phi_{0}}{e}$
Slope of straight line between $V$ and $v$ is $\frac{h}{e}\ \ h = e \times$ slope of straight line.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.