A certain certain metallic surface is illuminated with monochromatic light of λ wavelength the stopping potential for photoelectric current for this light is 3Vo. if the same surface is illuminated with light of wavelength 2λ the stopping potential is V the threshold wavelength for this surface for Photoelectric effect is
Answers
=> 4λ !
Explanation:
From photoelectric equation
hv = W + eVo [where, W = work function ]
So, hc / λ = W + 3eVo _[i]
Also, hc / 2λ = W + eVo
=> hc / λ = 2W + 2eVo _[ii]
Subtracting Eq [i] from Eq [ii] we get,
0 = W - eVo => W = eVo
From Eq [i]
hc / λ = eVo + 3eVo = 4eVo
The threshold wavelength is given by
λth = hc / W = 4eVoλ / eVo = 4λ
The threshold wavelength for this surface for Photoelectric effect is 4λ !
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Answer:
A certain metallic surface is illuminated with monochromatic light of wavelength λ. The stopping potential for photo-electric current for this light is 3V0. If the same surface is illuminated with light of wavelength 2λ, the stopping potential is V0.
A stopping potential of 0.82 V is required to stop the emission of photoelectrons from the surface of a metal by light of wavelength 4000Ao. For light of wavelength 3000Ao, the stopping potential is 1.85 V.