A student performs an experiment on photoelectric effect, using two materials A and B. A plot of `V_(stop) vs. nu` is given in fig.
(i) Which material A or B has a higher work function?
(ii) Given the electric charge of an electron `=1.6xx10^(-19)C`, find the value of h obtained from the experiment for both A and B. Comment on whether it is consistant with Eistein's theory.

Explanation

(i) Here, threshold frequency of A, `v_(0A)=5xx10^(14)Hz` and of B,
`v_(0B)=10xx10^(14)Hz`.
Work function, `phi_(0)=hv_(o) or phi_(0) prop v_(0)`
`:. (phi_(0A))/(phi_(0B))=(5xx10^(14))/(10xx10^(14))lt1 or phi_(0A)lt phi_(0B)`
Therefore, work function is higher for material B than A.
(ii) For metal A, `slope =h/e=2/((10-5)10^(14)) or h=(2xxe)/(5xx10^(14)) =(2xx1.6xx10^(-19))/(5xx10^(14)) =6.4xx10^(-34)Js`
For metal B, `slope =h/e=2/((15-10)10^(14)) or h=(2.5xxe)/(5xx10^(14)) =(2.5xx1.6xx10^(19))/(5xx10^(14)) =8xx10^(-34)Js`
Since, the value of h from experiment for metals A and B is different. Hence, experiment is not consistent with theory.