Q. Work function of a metal is $2.1\ eV.$ Which of the waves of the following wavelengths will be able to emit photoelectrons from its surface
A) $4000\ \mathring{\mathrm{A}},\ 7500\ \mathring{\mathrm{A}}$
B) $5500\ \mathring{\mathrm{A}},\ 6000\ \mathring{\mathrm{A}}$
C) $4000\ \mathring{\mathrm{A}},\ 6000\ \mathring{\mathrm{A}}$
D) None of these
Explanation
(d) Threshold wavelength $\lambda_{0} = \frac{12375}{2.1} = 5892.8\ \mathring{\mathrm{A}}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.