Photoelectric effect experiments are performed using three different metal plates $p, q$ and $r$ having work functions $\phi_p=2.0 \ eV, \phi_q=2.5 \ eV$ and $\phi_r=3.0 \ eV$,respectively. $A$ light beam containing wavelengths of $550 \ nm, 450 \ nm$ and $350 \ nm$ with equal intensities illuminates each of the plates. The correct $I-V$ graph for the experiment is:

The de-Broglie wavelength of an electron is the same as that of a photon. If the velocity of the electron is $25 \%$ of the velocity of light,then the ratio of the $K.E.$ of the electron to the $K.E.$ of the photon will be:

The radiation corresponding to $3 \rightarrow 2$ transition of a hydrogen atom falls on a metal surface to produce photoelectrons. These electrons are made to enter a magnetic field of $3 \times 10^{-4} \ T$. If the radius of the largest circular path followed by these electrons is $10.0 \ mm$,the work function of the metal is close to......$ eV$.

In the photoelectric effect:
$A.$ The photocurrent is proportional to the intensity of the incident radiation.
$B.$ The maximum kinetic energy with which photoelectrons are emitted depends on the intensity of incident light.
$C.$ The maximum kinetic energy with which photoelectrons are emitted depends on the frequency of incident light.
$D.$ The emission of photoelectrons requires a minimum threshold intensity of incident radiation.
$E.$ The maximum kinetic energy of the photoelectrons is independent of the frequency of the incident light.
Choose the correct answer from the options given below:

An electromagnetic wave of wavelength $\lambda$ is incident on a photosensitive surface of negligible work function. If the photoelectrons emitted from this surface have the de-Broglie wavelength $\lambda_{1}$,then:

The kinetic energy of emitted cathode rays is dependent on: