MHTCET 15 Apr 2026 Shift 1 Paper

Concept:For photoelectric emission, the stopping potential depends on the maximum kinetic energy of the emitted photoelectrons, which changes with the frequency of incident light.Explanation:According to Einstein's photoelectric equation,$$K_{\max} = h\nu - \phi$$Here, $h$ is Planck's constant, $\nu$ is the frequency of incident light, and $\phi$ is the work function of the material.Since frequency is related to wavelength by$$\nu = \frac{c}{\lambda}$$we can rewrite the equation as$$K_{\max} = \frac{hc}{\lambda} - \phi$$The stopping potential $V_0$ is related to the maximum kinetic energy by$$eV_0 = K_{\max}$$Therefore,$$eV_0 = \frac{hc}{\lambda} - \phi$$When the incident wavelength $\lambda$ is decreased, the term $\frac{hc}{\lambda}$ becomes larger.This means the maximum kinetic energy $K_{\max}$ of the emitted photoelectrons increases.Since $V_0 = \frac{K_{\max}}{e}$, an increase in $K_{\max}$ leads to an increase in the stopping potential $V_0$.Hence, the stopping potential increases when the wavelength of incident light decreases.Answer:The stopping potential increases.Correct option: B. increases