Question

Draw a plot of frequency v of incident radiations as a function of stopping potential V₀ for a given photo emissive material. What information can be obtained from the value of the intercept on the stopping potential axis?

Answer 1

The frequency and stopping potential would be plotted as a linear relationship with a positive slope, with the y-axis representing the stopping potential and the x-axis representing the frequency. The intercept on the y-axis, which represents the stopping potential at zero frequency (threshold frequency) where no photoelectrons are emitted, gives information about the material’s work function, specifically the negative value of the work function divided by the electron charge (−Φ/e).

eV₀ = hv − Φ 

Rearranging,

V₀ = `(h/e)v - phi/e`

y = mx + c

Y-intercept (c) = `-phi/e`