When a metallic surface is illuminated with radiation of wavelength λ, the stopping potential is V. If the same surface is illuminated with radiation of wavelength 2λ, the stopping potential is V/4. The threshold wavelength for the metallic surface is
A. 4λ
B. 5λ
C. \(\frac{5}{2}\)λ
D. 3λ
Answer:D
When a metallic surface is illuminated with radiation of wavelength λ, the stopping potential is V. If the same surface is illuminated with radiation of wavelength 2λ, the stopping potential is V/4. The threshold wavelength for the metallic surface is
A. 4λ B. 5λ C. \(\frac{5}{2}\)λ D. 3λ