A student performs an experiment on photoelectric effect using two materials A and B. A plot of stopping potential `(V_(0))` vs freqency (v) is as shown in the figure.

The value of h obtained from the experiment for both A and B respectively is
(Given electric charge of an electron `=1.6xx10^(-19)C)`

Options

A. `3.2xx10^(-34)Js,4xx10^(-34)Js`
B. `6.4xx10^(-34)Js,8xx10^(-34)Js`
C. `1.2xx10^(-34)Js,3.2xx10^(-34)Js`
D. `4.2xx10^(-34)Js,5xx10^(-34)Js`

Answer

B

Explanation

(b) :
For metal A, Slope `=(h)/(e)=(2-0)/((10-5)xx10^(14))`
`or h=(2xxe)/(5xx10^(14))=(2xx1.6xx10^(-19))/(5xx10^(14))=6.4xx10^(-34)J` s
For metal B, Slope `=(h)/(e)=(2.5-0)/((15-10)xx10^(14))`
` h=(2.5xxe)/(5xx10^(14))=(2.5xx1.6xx10^(-19))/(5xx10^(14))=8xx10^(-34)J` s