If a person wants to see an enlarged image of the object by using a convex lens then the lens must be held

Options

A. Close to the object so that the object lies within the focal length of the lens
B. Far from the object so that the object lies beyond 2F
C. At infinity
D. Far from the object so that the object lies at 2F.

Explanation

To determine how a person can see an enlarged image of an object using a convex lens, we need to understand the relationship between the object distance, the focal length of the lens, and the image formed.

### Step-by-Step Solution:

1. **Understanding the Convex Lens**: A convex lens is a converging lens that can produce both real and virtual images depending on the position of the object relative to the lens.

2. **Position of the Object**: To see an enlarged image, the object must be placed within the focal length of the lens. The focal length (f) is the distance from the lens to the focal point, where parallel rays of light converge.

3. **Ray Diagram**:
- Draw a convex lens and mark its focal points (F) on both sides.
- Place the object (O) between the lens and the focal point (F). This means the object distance (u) is less than the focal length (f).
- Draw two rays from the top of the object:
- One ray parallel to the principal axis that refracts through the focal point on the opposite side.
- Another ray passing through the center of the lens which continues in a straight line.

4. **Image Formation**: The two refracted rays will diverge after passing through the lens. If we extend these rays backward, they will appear to meet at a point, which is where the virtual image (I) is formed.

5. **Characteristics of the Image**: The image formed is virtual, upright, and enlarged. This is because the object is placed within the focal length of the lens.

6. **Conclusion**: Therefore, to see an enlarged image of the object using a convex lens, the lens must be held close to the object so that the object lies within the focal length of the lens.

### Final Answer:
The lens must be held close to the object so that the object lies within the focal length of the lens.

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