A magnifying lens has a focal length of 10 cm. (a) Where should the object be placed if the image is to be 30 cm from the lens ? (b) What will be the magnification ?

Explanation

To solve the problem step by step, we will use the lens formula and the magnification formula.

### Given:
- Focal length (f) = 10 cm (positive for a convex lens)
- Image distance (v) = -30 cm (negative because the image is on the same side as the object for a real image)

### Part (a): Finding the Object Distance (u)

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