What is the ratio of de Broglie wavelength of an electron to that of proton if the velocity of proton is $\frac{1}{6}$ the velocity of electron?

A monochromatic beam of photons of intensity to $1.5 \mathrm{Wm}^{-2}$ and energy 11.2 eV is incident on a material of work function 4.8 eV . What is the maximum speed of photoelectrons emitted due to photoelectric effect if, only $0.53 \%$ of the incident photons eject photoelectrons. Given mass of electron $m=9 \times 10^{-31} \mathrm{~kg}$.

The stopping potential when a metal surface is illuminated by light of wavelength $\lambda$ is 15 V . The stopping potential when the same surface is illuminated by light of wavelength $4 \lambda$ is 3 V . The ratio of threshold wavelength to the initial incident wavelength $\lambda$ is:

A plot of kinetic energy of emitted photoelectrons from a metal versus the frequency of incident radiation gives a straight line, the intercept of which

A. Depends on the nature of the metal used

B. Depends on the intensity of radiation

C. Depends both on the intensity and the nature of metal used

D. Is a constant and is same for all metals which is independent of the intensity of Incident radiation