A microscope consisting of two convex lenses of focal lengths 2 cm and 5 cm placed 20 cm apart. Where must the object be placed so that the final image (virtual) is at a distance of 25 cm from eye ?

Explanation

To solve the problem step-by-step, we will use the lens formula and the information provided about the microscope consisting of two convex lenses.

### Step 1: Understand the setup
We have two lenses:
- Objective lens (focal length \( f_0 = 2 \, \text{cm} \))
- Eyepiece (focal length \( f_e = 5 \, \text{cm} \))
The distance between the two lenses is \( d = 20 \, \text{cm} \).

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