An astronomical telescope has an eyepiece of focal-length 5cm. If the angular magnification in normal adjustment is 10, when final image is at least distance of distinct vision (25cm) from eye piece, then angular magnification will be :

Options

A. 10
B. 12
C. 50
D. 60

Explanation

To solve the problem of finding the angular magnification of an astronomical telescope when the final image is at the least distance of distinct vision (25 cm) from the eyepiece, we can follow these steps:

### Step 1: Understand the Given Information
We know:
- Focal length of the eyepiece (Fe) = 5 cm
- Angular magnification in normal adjustment (M_normal) = 10
- Least distance of distinct vision (D) = 25 cm

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