NEET Questions

In Lenard's experiment, the stopping potential for photoelectrons emitted from a metal surface illuminated by light of wavelength $\lambda_1$ is $V_1$. When the wavelength is changed to $\lambda_2$ ($\lambda_2 > \lambda_1$), the stopping potential becomes $V_2$. If the work function of the metal is $\phi$, which of the following relations is correct?

Two different metals M1 and M2 have work functions $\phi_1$ and $\phi_2$ respectively, where $\phi_1 > \phi_2$. If both metals are illuminated with light of the same frequency $

u$, such that$h

u > \phi_1$, which metal will exhibit a larger stopping potential?

A photocell with a work function of 2.5 eV is illuminated by light of wavelength 400 nm. What is the maximum speed of the emitted photoelectrons? (Planck's constant $h = 6.63 imes 10^{-34}$ Js, speed of light $c = 3 imes 10^8$ m/s, mass of electron $m_e = 9.11 imes 10^{-31}$ kg)

If the frequency of incident light on a photocell is doubled, keeping the intensity constant, how does the stopping potential change?

Two different metals, M1 and M2, are used as the cathode in separate photoelectric experiments. M1 has a larger work function than M2. If both metals are illuminated with light of the same frequency and intensity, which of the following is TRUE?

The work function of a metal is $\phi$. Light of frequency $2

u$(where$

u = \frac{\phi}{h}$) is incident on the metal. If the frequency is now reduced to$\frac{3

u}{2}$, and the intensity is doubled, what will be the ratio of the new saturation current to the original saturation current?

A metal surface is illuminated by light of frequency $2

u_0$, where$

u_0$ is the threshold frequency. If the intensity of the light is doubled, the maximum kinetic energy of the emitted photoelectrons will:

Two different metals, M1 and M2, have work functions $\phi_1$ and $\phi_2$ respectively, where $\phi_1 > \phi_2$. If both metals are illuminated with light of the same frequency $

u$, such that$

u > \frac{\phi_1}{h}$, which metal will exhibit a larger stopping potential?

A photon of energy $3eV$ is incident on a metal surface having a work function of $2eV$. If the photon is absorbed, the maximum velocity of the emitted photoelectron is approximately (mass of electron $m_e = 9.1 imes 10^{-31} kg$):

The stopping potential for photoelectrons emitted from a metal surface illuminated by light of wavelength $\lambda$ is $V_0$. If the wavelength is reduced to $\lambda/2$, keeping the intensity constant, the new stopping potential will be: