How Do You Calculate the Focal Length of a Microscope's Eyepiece?

[kbray278]

Homework Statement

The near point of a naked eye is 25 cm. When placed at the near point and viewed by the naked eye, a tiny object would have an angular size of 5.2X10-5 rad. When viewed through a compound microscope, however, it has an angular size of -9.20X10-3 rad. (The minus sign indicates that the image produced by the microscope is inverted.) The objective of the microscope has a focal length of 2.8 cm, and the distance between the objective and the eyepiece is 16 cm. Find the focal length of the eyepiece.

Homework Equations

M=(L-Fe)(N)/FoFe

The Attempt at a Solution

Tried using the equation and solved for Fe and got the answer 15.98 but it was wrong. Any Ideas?

 

[rl.bhat]

The magnification M = angular size of the image/ angular size of the object. Find M.
Now M = 25/f(effective), where f(effective) is given by
1/f(effective) = 1/fo + 1/fe - d/fo*fe
where fo...>focal length of the objective
fe...>focal length of the eye-piece
and d...>distance between objective and eye-piece.

 

[nlightner]

As a scientist, it is important to carefully consider all factors and variables in order to accurately solve a problem. In this case, it is important to clarify the units being used in the given data. The near point of the naked eye is typically measured in meters, while the focal length of a microscope is typically measured in centimeters. This discrepancy in units could potentially lead to an incorrect solution.

Additionally, it is important to double check the calculations and make sure all values are being used correctly in the equation. It may also be helpful to convert all units to a consistent system (e.g. meters or centimeters) before solving the problem.

Furthermore, it is important to consider the assumptions and limitations of the equation being used. In this case, the equation assumes that the object being viewed is located at the focal point of the objective lens. This may not be the case in all scenarios and could lead to an inaccurate solution.

In conclusion, as a scientist, it is important to carefully analyze and consider all factors and assumptions when solving a problem. It may also be helpful to seek guidance or clarification from a mentor or colleague if difficulties arise.