In photoelectric emission process from a metal of work function 1.8 eV, the kinetic energy of most energetic electrons is 0.5 eV. The corresponding stopping potential is

When monochromatic radiation of intensity $$I$$ falls on a metal surface, the number of photoelectrons and their maximum kinetic energy are N and T respectively. If the intensity of radiation is 2$$I$$, the number of emitted electrons and their maximum kinetic energy are respectively

The electron in the hydrogen atom jumps from excited state (n = 3) to its ground state (n = 1) and the photons thus emitted irradiate a photosensitive material. If the work function of the material is 5.1 eV, the stopping potential is estimated to be (the energy of the electron in n^th state E_n = $${{ - 13.6} \over {{n^2}}}eV$$)

A source S₁ is producing, 10¹⁵ photons per second of wavelength 5000 $$\mathop A\limits^ \circ $$. Another source S₂ is producing 1.02 $$ \times $$ 10¹⁵ photons per second of wavelength 5100 $$\mathop A\limits^ \circ $$. Then, (power of S₂)/(power of S₁) is equal to