Final answer:
The dial reading for adapters or extensions in physics is calculated using either the microscope's resolving power formula or the magnification equation. The former is more accurate, considering factors like wavelength and aperture size, while the latter is a simpler approximation for small changes in levels.
Step-by-step explanation:
The formula for determining the dial reading when adapters or extensions are used in physics can vary depending on the specific context. However, based on the given information, it appears the question may refer to calculations involving a microscope's resolving power or magnification. For a microscope's resolving power (A0), when the wavelength of the incident radiation is 1.0 pm and the diameter of the aperture is D = 2.0µm, a specific formula would be used. Alternatively, for magnification calculations, the equation m = -di/do is used, where 'di' represents the image distance, 'do' the object distance, and 'm' the magnification. This would provide an approximation that's suitable for small changes in levels.
For more accurate measures, especially when dealing with larger changes in levels or precision instruments such as microscopes, the resolving power equation should be used. This ensures that factors like wavelength and aperture size are taken into consideration for a more precise dial reading.