NEET Physics MCQs

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?

In Lenard's experiment, if the intensity of the incident light is doubled while keeping the frequency constant, what will be the effect on the stopping potential?

A metal surface with work function $\phi$ is illuminated by monochromatic light of frequency $

u$. If the stopping potential is$V_0$, and the mass of an electron is$m$, the maximum speed of the emitted photoelectrons is:

In Lenard's experiment, ultraviolet light of wavelength 200 nm is incident on a metal surface. The stopping potential is found to be 4V. If the wavelength is increased to 300 nm, what will be the new stopping potential? (Take $h = 6.63 imes 10^{-34}$ Js, $c = 3 imes 10^8$ m/s, $e = 1.6 imes 10^{-19}$ C)

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 is illuminated by a monochromatic light source with intensity $I$ and frequency $

u$. If the intensity is doubled while keeping the frequency constant, which of the following statements is TRUE regarding the photocurrent and stopping potential?

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?

A photocell is connected in series with a variable resistor and a sensitive ammeter. The cathode of the photocell is illuminated with monochromatic light of constant intensity. As the resistance of the variable resistor is increased, what happens to the photocurrent and the stopping potential?

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?