Photoelectric EffectHard

Question

When a centimeter thick surface is illuminated with light of wavelength λ, the stopping potential is V. When the same surface is illuminated by light of wavelength 2λ, the stopping potential is V/3. The threshold wavelength for the surface is :

Options

A.4λ/3
B.4λ
C.6λ
D.8λ/3

Solution

= φ + eV     ......(i)
= φ +      ......(ii)
⇒ = 2φ       ⇒ φ =
∴ λth = 4λ

Create a free account to view solution

View Solution Free
Topic: Photoelectric Effect·Practice all Photoelectric Effect questions

More Photoelectric Effect Questions

For photo-electric effect with incident photon wavelength λ, the stopping potential is V0. Identify the correct var...When electron is incident on molyblednum then by changing energy of electron :-...for maximum λ = (n1 = 2 → n2 = 1 Lymen (n1 = 3 → n2 = 2 BalmerLongest λLymen = Longest λBalme...Longitudinal strain is possible in:...Two identical samples (same material and same amount initially) P and Q of a radioactive substance having mean life T ar...