JEE MAIN - Physics (2025 - 29th January Evening Shift - No. 2)
In an experiment with photoelectric effect, the stopping potential,
is $\left(\frac{1}{e}\right)$ times the maximum kinetic energy of the emitted photoelectrons
increases with increase in the intensity of the incident light
decreases with increase in the intensity of the incident light
increases with increase in the wavelength of the incident light
Explanation
We know, $$e{V_0} = hv - \phi $$ .... (i)
$$ \Rightarrow e{V_0} = K{E_{\max }}$$ (where $\phi$ = work function of the metal and $v_0$ = stopping potential)
$$ \Rightarrow {V_0} = \left( {{1 \over e}} \right)K{E_{\max }}$$
Stopping potential depends solely on the frequency of the incident light $+(v)$ & the work function of the metal, not the intensity.
From eq. (i), we can see,
$$v \uparrow \Rightarrow {v_0} \uparrow $$
$$ \Rightarrow {e \over {\lambda \downarrow }} \Rightarrow {v_0} \uparrow $$ (as $$v = {c \over \lambda }$$)
So, stopping potential increases with decrease in the wavelength of the incident light.
Hence, option 1 is correct.
Comments (0)
