A point source is placed on the axis of a symmetrical convex lens of focal length 20 cm at a distance of 40cm. If the lens is raised by 1cm, by how much will the image be lifted relative to the previous axis?

Explanation

To solve the problem step by step, we will follow the lens formula and the concept of magnification.

### Step 1: Understand the given data
- Focal length of the convex lens, \( F = 20 \, \text{cm} \)
- Object distance, \( u = -40 \, \text{cm} \) (negative because the object is on the same side as the incoming light)
- The lens is raised by \( 1 \, \text{cm} \)

### Step 2: Use the lens formula
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