In a phtoelectric experiment, ultraviolet light of wavelength 280 nm is used with lithium cathode, having work function Φ=25 eV. If the wavelength incident light is switched to 400 nm, find out the change in the stopping potential.
(h=6.63×10⁻³⁴ Js, c=3×10⁸ ms⁻¹)
A. 0.6 V
B. 1.1 V
C. 1.9 V
D. 1.3 V
