Final Answer:
The magnifying lens in the image intensifier tube focuses and magnifies the output image, determining the amount of magnification in the virtual image. Therefore, the corect answer is option 2) magnifying lens.
Step-by-step explanation:
In an image intensifier tube, the magnifying lens plays a crucial role in determining the degree of magnification in the virtual image. Image intensifier tubes are used in medical imaging to enhance low levels of light, such as X-rays, to create a brighter and more detailed image. The magnifying lens, situated within the tube, is responsible for focusing and magnifying the output image.
The process involves electrons emitted by a photocathode striking a phosphor screen, producing light. This light is then captured and intensified by the magnifying lens, which focuses it to create a virtual image. The magnification is a result of the curvature and refractive properties of the lens.
The other components mentioned—focusing cup, electrostatic lens, and accelerating anode—serve different functions within the image intensifier tube. The focusing cup helps direct the electron beam, the electrostatic lens focuses the beam, and the accelerating anode accelerates the electrons towards the output screen.
While these components are crucial for the overall function of the image intensifier, the magnifying lens specifically influences the degree of magnification in the final virtual image, making it the correct answer in this context.
Therefore, the corect answer is option 2) magnifying lens.