In the Thomson spectrograph experiment,four positive ions $P, Q, R,$ and $S$ are situated on the $Y-X$ curves as shown in the figure.

The kinetic energy of emitted cathode rays is dependent on:

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$.

An electron is moving through a field. It is moving $(i)$ opposite to an electric field and $(ii)$ perpendicular to a magnetic field as shown. For each situation,determine the de-Broglie wavelength of the electron.

The spectrum obtained from an electric lamp or a red-hot heater is:

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: