Question : Using the graph shown in the figure for stopping potential V/s the incident frequency of photons, calculate Planck’s constant.
Doubt by Safir
Solution :
We know, the slope of stopping potential (V₀) and frequency of incident radiation (ν) gives h/e.
Slope = h/e
So, Planck constant (h) = Slope×e
h = tanθ × e
h= (Perpendicular/Base)×e
h= {(1.23-0)/[(8-5)×1014]}×[1.6×10-19]
h= [(1.23×1.6)/3]×10-19-14
h = 0.656×10-33
h = 6.56×10-34
h = 6.6×10-34 Js
