Doubt by Nandkishor Rathod

sir, Q. 21 ???

Answers

Answer by

Hi Nandkishore, 

from Einstein's Photoelectric equation,

hv = hvo + KEmax

Also,

KEmax = eV where V is the stopping potential

so,  hv = hvo + eV 

v = (e/h)V + vo      (dividing by h)

comparing this equation by equation of straight line, y = mx + c where m is the slope.

e/h = slope 

Also, slope = ab/cb (from the figure)

e/h = ab/cb

so, h = e(cb/ab)   

Hope you understand this explanation. Let me know if you have any doubt.