The electric field associated with a light wave is given by
E = E0 sin [(1.57 × 107 m–1) (x – ct)].
Find the stopping potential when this light is used in an experiment on photoelectric effect with the emitter having work function 1.9 eV.
Given, work function Ф =1.9 eV
On comparing the above two equations, we get
We know that λ=c/f……. (4)
Where λ is the wavelength of light,
C is the speed of the light,
f is the frequency of the light.
∴ From eq (3) & (4)we get the value of frequency
Now, from Einstein’s photoelectric equation
Where h is the Planck’s constant,
f is the frequency of light,
e is the charge on an electron ,
is the stopping potential,
Ф is the work function.
Putting the values in eq(5) we have,
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