The anode voltage of a photocell is kept fixed. The wavelength $\lambda$ of the light falling on the cathode is gradually changed. The plate current $I$ of the photocell varies as follows:

The anode voltage of a photocell is kept constant. The wavelength of the incident light on the cathode is changed gradually. Then,the photoelectric current $I$ of the photocell varies according to which of the following graphs?

If $m$ is the mass of an electron and $c$ is the speed of light,then the ratio of the wavelength of a photon of energy $E$ to the wavelength of an electron of the same energy is:

An electron moving with speed $v$ and a photon moving with speed $c$ have the same de Broglie wavelength. The ratio of the kinetic energy of the electron to that of the photon is -

In a photocell,bichromatic light of wavelengths $2475 \ \mathring{A}$ and $6000 \ \mathring{A}$ is incident on a cathode whose work function is $4.8 \ eV$. If a uniform magnetic field of $3 \times 10^{-5} \ T$ exists parallel to the plate,the radius of the path described by the photoelectron will be ............ $cm$ (mass of electron $= 9 \times 10^{-31} \ kg$).

In a photoelectric effect experiment,three different metal plates $p, q,$ and $r$ have work functions $\phi_p = 2.0 \ eV, \phi_q = 2.5 \ eV,$ and $\phi_r = 3.0 \ eV$. The incident light beams have wavelengths $\lambda_p = 550 \ nm, \lambda_q = 450 \ nm,$ and $\lambda_r = 350 \ nm$. The intensity of light is the same for each plate. The correct $I-V$ graph for the experiment is: $[hc = 1240 \ eV \ nm]$