MCQ
light of wavelength $\lambda$ strikes a photo-sensitive surface and electrons are ejected with kinetic energy $E$. If the kinetic energy is to be increased to $2\ E$, the wavelength must be changed to $\lambda^{\prime}$ where
- A$\lambda^{\prime}=\frac{\lambda}{2}$
- B$ \lambda^{\prime}=2 \lambda$
- ✓$\frac{\lambda}{2}<\lambda^{\prime}<\lambda$
- D$\lambda^{\prime}>\lambda$
