Q. In a photoelectric experiment for $4000\ \mathring{\mathrm{A}}$ incident radiation, the potential difference to stop the ejection is $2V.$ If the incident light is changed to $3000\ \mathring{\mathrm{A}},$ then the potential required to stop the ejection of electrons will be
A) $2\ V$
B) Less than $2V$
C) Zero
D) Greater than $2\ V$
Explanation
(d) According to Einstein’s photoelectric equation
$E = W_{0} + K_{\max} \Rightarrow V_{0} = \frac{hc}{e}\left\lbrack \frac{1}{\lambda} - \frac{1}{\lambda_{0}} \right\rbrack$
Hence if $\lambda$ decreases $V_{0}$ increases
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.