Q. In photoelectric effect, the stopping potential $(V_0)$ v/s frequency $(\nu)$ curve is plotted. ( h is the Planck's constant and $\phi_0$ is work function of metal ) (A) $V_0$ v/s $\nu$ is linear. (B) The slope of $V_0$ v/s $\nu$ curve $=\frac{\phi_0}h$ (C) h constant is related to the slope of $V_0$ v/s $\nu$ line. (D) The value of electric charge of electron is not required to determine $h$ using $V_0$ v/s $\nu$ curve. (E) The work function can be estimated without knowing the value of $h$. Choose the correct answer from the options given below :
A) (C) and (D) only
B) (A), (C) and (E) only
C) (A), (B) and (C) only
D) (D) and (E) only
Explanation
[Solution by Dr. Abubacker] $eV_0=h\nu-\phi_0$, so $V_0$ vs $\nu$ is a straight line (A true) with slope $\frac he$ (B false); $h$ follows from the slope (C true) but only if $e$ is known (D false). The intercept on the $V_0$ axis gives $-\frac{\phi_0}e$, so $\phi_0$ can be found without using $h$ (E true). So (A), (C), (E). (Medium confidence on E: it follows the official key.) Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.