The above graph shows frequency of an incident photon and maximum kinetic energy of a photoelectric effect

a. What is the value of threshold frequency and threshold wave-length?
b. What is the work function of the cathode in eV?
c. Find the maximum kinetic energy, if the frequency of photon is `9xx10^(14)`Hz.
d. Also find the value of Planck's constant (h).

Explanation

a. `3xx10^(14)Hz, 10^(-6)m`
b. 2eV
c. `KE=hupsilon-phi_(0)=3.85eV =4eV` (0.4eV from graph)
d. From the graph, slope `=(4eV)/(9xx10^(14)), (h)/( e )= (4eV)/(9xx10^(14)), e=1.6xx10^(-19)C`
`therefore h=(4xx1.6xx10^(-19))/(9xx10^(14))~~7xx10^(-34)Js`
[Actual value of `h=6.63xx10^(-34)Js`]