What is true about electromagnetic deflection CRT usage?

Electromagnetic deflection in cathode ray tubes (CRTs) utilizes electric fields applied to deflection plates or anodes to control the trajectory of the electron beam. This method is crucial for steering the beam accurately across the screen to create images. By applying voltage to these plates, the electric field alters the path of the electrons as they travel from the cathode towards the phosphorescent screen. The ability to manipulate the beam in this manner enables precise control over pixel rendering, which is essential for clear and detailed display outputs.

The other options do not accurately represent the functionalities of electromagnetic deflection CRTs. For instance, the notion that these devices operate without electric fields contradicts the fundamental principle of their operation, which is reliant on precisely controlled electric fields to achieve deflection. While some may prefer simpler mechanisms for particular applications, electromagnetic deflection is selected for its capability to provide rapid and accurate positioning of the electron beam, not simplicity. Additionally, the concept of having no deflection sensitivity is false; CRTs exhibit significant deflection sensitivity, which allows them to create detailed images.