What is the primary function of the CRT's deflection coils?

The primary function of the deflection coils in a cathode ray tube (CRT) is to control the movement of the electron beam. These coils create magnetic fields that interact with the charged electrons emitted from the cathode, enabling precise steering of the beam across the screen. This movement is essential for displaying images, as it allows the electron beam to scan from left to right and top to bottom, illuminating phosphors on the screen to create the desired visual output.

The deflection of the beam is critical to the overall functionality of CRTs, as it determines how and where the image is formed on the screen. Without the ability to control this movement effectively, the display would be chaotic and unusable.