In a photoelectric effect experiment, the graph between the stopping potential (V) and frequency (v) of the incident radiations on two different metal plates P and Q are shown in plates, P and Q has greater value of work function ? (ii) What does the slope of the lines depict?

Explanation

(i) As the threshold frequency is higher for metal Q than that of metal P, hence the work function `phi_0=hv_0`, is greater for metal Q than that of P.
(ii) `eV=hv-phi_0` or `V=(hv)/e-(phi_0)/e`
`DeltaV=h/eDeltav or (DeltaV)/(Deltav)=h/e`
Slope of the line `=(DeltaV)/(Deltav)=h/e`
Where h is the planck's constant and e is the electronic charge.