When light of wavelength 350 nm is incident on a metal surface, the stopping potential of the photoelectrons is measured to be 0.500 v. what is the work function of this metal? (c = 3.00 × 108 m/s, h = 6.626 × 10-34 j ∙ s, 1 ev = 1.60 × 10-19 j) 3.05 ev 4.12 ev 3.54 ev 0.500 ev

3.05 eV

Explanation:

Given

wavelength of light

Stopping Potential

and We know Energy of an incoming light is given by

or

From Einstein Photo Electric Equation

and Stopping Potential is equal to gain in kinetic Energy by ejected Electron

their crystal patterns have been disrupted by stress

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.