Q. Five elements $A,B,C,D$ and $E$ have work functions $1.2\ eV,\ 2.4\ eV,\ 3.6\ eV,\ 4.8\ eV$ and $6\ eV$ respectively. If light of wavelength $4000\ \mathring{\mathrm{A}}$ is allowed to fall on these elements, then photoelectrons are emitted by
A) $A,B$ and $C$
B) $A,B,C,D$ and $E$
C) $A$ and $B$
D) Only $E$
Explanation
(c) $E = \frac{12375}{4000} = 3.09\ eV$ Photoelectrons emit if energy of incident light > work function
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.