Question

A metallic surface is illuminated with radiation of wavelength λ , the stopping potential is V₀. If the same surface is illuminated with radiation of wavelength 2λ , the stopping potential becomes V₀/4. The threshold wavelength for this metallic surface will be

(1) λ/4 

(2) 4λ

(3) 3/2λ 

(4) 3λ

Answer 1

Correct option is (4) 3λ

From the equation of photoelectric effect