By how much would the stopping potential for a given photosensitive surface go up if the frequency of the incident radiations were to be increased from 4×10¹⁵ Hz to 8 × 10¹⁵ Hz
Given h = 6.4 X 10⁻³⁴ J - s , e= 1.6 X 10⁻¹⁹Cand c= 3 X 10⁸ms⁻¹