If a final image is formed at a distance of 25 cm from the eyepiece of a microscope with a total magnification of 330 times. Calculate length of the microscope. If the focal length of the objective lens is 0.5 cm and the eyepiece lens is 2.5 cm.

= 1.0). An object (A) is Assume that a thin lens (r, placed in the left side of lens (d = 45mm) and the image of the object is located in the right side of the lens at position (B) (d' = 90mm). 1) Compute the refraction index of the lens (n2); = -r2 = 40mm) is placed in the air (n 2) If placing another negative thin lens (f2 = -180mm) immediately behind the first lens to create a doublet lens in which the spacing between two lenses is zero (as shown in the right figure), what is the focal length of this doublet? 3) Where is the final image position (C) of the object (A) through this new doublet? (Note: Assuming this doublet lens is a combined thin lens too without considering its thickness).

A microscope has an objective lens with a focal length of 16.22 mm and an eyepiece with a focal length of 9.28 mm. With the length of the barrel set at 35.0 cm, the diameter of a red blood cell's image subtends an angle of 1.43 mrad with the eye. If the final image distance is 35.0 cm from the eyepiece, what is the actual diameter of the red blood cell? Hint: To solve this equation, go back to basics and use the thin-lens equation. um

A microscope objective with a magnification of 20 is used in a microscope with a magnification of 56. Find the focal length of the ocular if the ocular's image is formed at the eye's near point, 27 cm from the eye. Neglect the distance between the eye and the ocular.