Question

Light of wavelength λ strikes a photosensitive surface and electrons are ejected with kinetic energy E. If the KE is to be increased to 2E, the wavelength must be changed to λ' where–

• A. λ' = λ/2
• B. λ' = 2λ
• C. λ' >λ
• D. $\frac { \lambda } { 2 }$<λ' <λ

Answer 1

Answer: (D)

$\frac { \lambda } { 2 }$<λ' <λ

Answer 2

If wavelength becomes halved than maximum KE becomes more than double.