(a) Define the terms, (i) threshold frequency, and (ii) stopping potential in the context of photoelectric effect.
(b) Draw a graph showing the variation of stopping potential with frequency
of incident radiation for a given photosensitive material.
(a) i) Threshold frequency:- it is the minimum frequency requested for the emission of electrons from a metal surface when lights fall on it. The threshold frequency is constant for the given material.
ii) Stopping potential:- It is the minimum negative potential given to the anode plate of the photoelectric tube. for which the photocurrent stops. it is denoted as .
b)
* It shows that stopping potential has a linear relation with the frequency of incident radiation.
* It shows that at a certain cut-off frequency to the stopping potential is zero.
* Here, the slope of the graph is equal which means it does not depend on nature of the material, slope equals to (from einstein's equation).