Verified Solution • 2025–26 Session moderate

QJEEM25Pheb74: JEE Main 2025 Physics - Class 12 JEEM25Pheb74 Solution: In an experiment with photoelectric effect, the stopping…

In an experiment with photoelectric effect, the stopping potential,

Multiple Choice Options

  • A is (1e)\left(\frac{1}{e}\right) times the maximum kinetic energy of the emitted photoelectrons
  • B increases with increase in the intensity of the incident light
  • C decreases with increase in the intensity of the incident light
  • D increases with increase in the wavelength of the incident light

Step-by-Step Verified Solution

We know, eV0=hv−ϕe{V_0} = hv - \phi .... (i)

⇒eV0=KEmax⁡\Rightarrow e{V_0} = K{E_{\max }} (where ϕ\phi = work function of the metal and v0v_0 = stopping potential)

⇒V0=(1e)KEmax⁡\Rightarrow {V_0} = \left( {{1 \over e}} \right)K{E_{\max }}

Stopping potential depends solely on the frequency of the incident light +(v)+(v) & the work function of the metal, not the intensity.

From eq. (i), we can see,

v↑⇒v0↑v \uparrow \Rightarrow {v_0} \uparrow

⇒eλ↓⇒v0↑\Rightarrow {e \over {\lambda \downarrow }} \Rightarrow {v_0} \uparrow (as v=cλv = {c \over \lambda } )

So, stopping potential increases with decrease in the wavelength of the incident light.

Hence, option 1 is correct.

Related Learning Resources & Exam Preparation