An object is placed at a distance of 10 cm from a concave mirror. When the distance of object from the mirror is decreased to 6 cm, the image gets 2 times magnified than that in first case. Calculate the focal length of the mirror.

Explanation

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

### Step 1: Understand the given data
- Initial object distance (u1) = -10 cm (negative as per sign convention for concave mirrors)
- New object distance (u2) = -6 cm
- The image formed at the new object distance is 2 times magnified compared to the first image.

### Step 2: Write the magnification formulas
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