(a) An object is seen through a simple microscope of focal length `12cm`. Find the angular magnification produced if the image is formed at the near point of the eye which is `25cm` away from it.
(b) A `10D` lens is used as a magnifier. Where should the object be placed to obtain maximum angular magnification for a normal eye (near point `= 25cm)`?

Explanation

To solve the problem step by step, we will address both parts (a) and (b) of the question.

### Part (a)

**Given:**
- Focal length of the lens, \( f = 12 \, \text{cm} \)
- Image distance (near point), \( v = -25 \, \text{cm} \) (negative because the image is virtual)

...