Which component controls the electron beam in the television camera tube?

The correct answer is the deflecting coils, which play a critical role in controlling the electron beam in a television camera tube. These coils are electromagnetic devices that create a magnetic field to influence the path of the electron beam emitted from the electron gun. By varying the current flowing through these coils, the beam can be deflected to precisely hit different locations on the signal plate, allowing for the scanning of an image.

The electron gun is responsible for emitting the electrons that form the beam, but it does not control the direction or focus of the beam once it is generated. The signal plate serves to collect the electrons and convert them into a video signal but does not have a role in directing the beam itself. Therefore, while all these components work together in the functioning of the television camera tube, the deflecting coils are specifically tasked with controlling the electron beam.