The ratio of the wavelength of a photon of energy $E$ to that of an electron of the same energy is ($m=$ mass of an electron,$c=$ speed of light,$h=$ Planck's constant).

Assertion $(A)$: Photoelectric effect demonstrates the wave nature of light.
Reason $(R)$: The number of photoelectrons is directly proportional to the frequency of light.

The anode voltage of a photocell is kept constant. The wavelength of the light incident on the cathode is changed gradually. Which of the following graphs represents the variation of the photoelectric current $(I)$ with the wavelength $(\lambda)$?

The correct curve between the stopping potential $(V_s)$ and intensity of incident light $(I)$ is

Assertion $(A)$: In the photoelectric effect,on increasing the intensity of light,both the number of electrons emitted and the kinetic energy of each of them increase,but the photoelectric current remains unchanged.
Reason $(R)$: The photoelectric current depends only on the wavelength of light.

$A$ photon and an electron have equal energy $E$. The ratio $\lambda_{\text{photon}} / \lambda_{\text{electron}}$ is proportional to: