Answer: Explanation:
1.)The 4X lens is called the scanning or low power lens. It has the widest field of view, allowing you to look at large parts of the specimen, and the greatest depth of field. The 10X lens is sometimes called medium power because it produces mid-range magnification.
2.)For example, an eyepiece having a magnification of 10x typically has a field number ranging between 16 and 18 millimeters, while a lower magnification eyepiece (5x) has a field number of about 20 millimeters.
3.)Oil immersion is the technique of using a drop of oil to wet the top of the specimen or slide cover and the front of the objective lens. This effectively immerses or bathes the light path between the lens and object viewed, allowing finer details to be seen.
