Question

The work functional of Silver and Sodium are $4.6$ and $2.3\text{eV},$ respectively. The ratio of the slope of the stopping potential versus frequency plot for Silver to that of Sodium is

Answer 1

According to Einstein’s photoelectric equation

$K_{max}=hv-{\varphi }_0$

$\text{But}{K}_{max}=e{V}_s$

Where $V_S$ is the stopping potential $V_s=\frac{h}{e}v-\frac{{\varphi }_0}{e}$

Thus, the graph between $V_s\text{vs}v$ is a straight line.

Compare the above relation with $y=mx+C$

$\therefore$ Slope of $V_s\text{vs}v$ graph $=\frac{h}{e}$

It is same for both the metals.

∴ Ratio of the slope $=1$