NEET Physics Dual Nature of Matter and Radiation MCQs

In Lenard's photoelectric experiment, which observation definitively proves the particle nature of light?

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?

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?

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:

A metal has a work function $\phi$. Light of frequency $

u_1$produces photoelectrons with maximum kinetic energy$K_1$. When the frequency is increased to$

u_2$, the maximum kinetic energy becomes$K_2$. Which of the following expressions correctly relates$\phi$,$

u_1$,$

u_2$,$K_1$, and$K_2$?

If the frequency of incident light in Lenard's experiment is doubled, keeping the intensity constant, what will happen to the number of photoelectrons emitted per second?

A proton with de-Broglie wavelength $\lambda_0$ enters a region of uniform electric field $\vec{E} = -E_0\hat{i}$. Which of the following graphs correctly represents the variation of its de-Broglie wavelength ($\lambda$) with time ($t$)?

The work function of a metal is doubled. If the incident light frequency remains the same, what will happen to the maximum kinetic energy of the emitted photoelectrons?