Which of the following can be used to form a real image?

Options

A. Concave mirror only
B. Plane mirror only
C. Convex mirror only
D. Both concave and convex mirrors.

Answer

To determine which of the following can be used to form a real image, we need to analyze the properties of different types of mirrors: concave mirrors, convex mirrors, and plane mirrors.

### Step-by-Step Solution:

1. **Understanding Image Formation by Mirrors**:
- Mirrors can form two types of images: real and virtual. A real image can be projected onto a screen, while a virtual image cannot.

2. **Analyzing Plane Mirrors**:
- A plane mirror always produces a virtual image. The image is laterally inverted and appears to be the same distance behind the mirror as the object is in front. Therefore, a plane mirror cannot form a real image.

3. **Analyzing Convex Mirrors**:
- A convex mirror is curved outward. When parallel rays (like those from a distant object) strike a convex mirror, they diverge after reflection. If we trace these rays backward, they appear to come from a point behind the mirror, forming a virtual image. Thus, a convex mirror cannot form a real image.

4. **Analyzing Concave Mirrors**:
- A concave mirror is curved inward. It can form both real and virtual images depending on the position of the object relative to the focal point.
- If the object is placed beyond the center of curvature, a real image is formed.
- If the object is placed between the focal point and the mirror, a virtual image is formed.
- Therefore, a concave mirror can indeed form a real image when the object is placed at a suitable distance.

5. **Conclusion**:
- Among the options provided, only the concave mirror can be used to form a real image.

### Final Answer:
**Concave mirror only can be used to form a real image.**

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