In a photocell circuit the stopping potential, `V_0`, is a measure of the maximum kinetic energy of the photoelectrons. The following graph shows experimentally measured values of stopping potential versus frequency v of incident light.

The values of Planks constant and the work function as determined from the graph are (taking the magnitude of electronic charge to be `e= 1.6 xx 10^(-19)C`)

Options

A. `6.4 xx10^(-34) Js,2.0 eV`
B. `6.0 xx10^(-34) Js,2.0 eV`
C. `6.4 xx10^(-34) Js,3.2 eV`
D. `6.0 xx10^(-34) Js,3.2 eV`

Answer

B

Explanation

`V=(hv)/e-phi`
Hence from graph `phi=2eV`
`h/e` = Slope
`=6/(1.6 xx10^(15))implies h=(6xx1.6 xx10^(-19))/(1.6 xx10^(15))=6.0 xx10^(-34)`