A beam of light incident on a plane mirror forms a real image on reflection. The incident beam is

Options

A. parallel
B. convergent
C. divergent
D. any of the above

Explanation

To determine the type of incident beam of light that forms a real image upon reflection from a plane mirror, we can analyze the characteristics of the different types of beams: parallel, convergent, and divergent.

### Step-by-Step Solution:

1. **Understanding Image Formation**:
- A real image is formed when light rays converge at a point after reflection. This means that the rays actually meet at a point in space.

2. **Analyzing the Types of Beams**:
- **Parallel Beam**: If a parallel beam of light strikes a plane mirror, the rays will reflect off the mirror and remain parallel. Since they do not converge, they will not form a real image.
- **Convergent Beam**: A convergent beam of light is one where the rays are coming together at a point. When this type of beam strikes a plane mirror, the rays will reflect and continue to converge, thus forming a real image.
- **Divergent Beam**: A divergent beam of light spreads out from a point source. When this beam reflects off a plane mirror, the rays will continue to diverge. This results in a virtual image, as the rays appear to come from a point behind the mirror.

3. **Conclusion**:
- The only type of incident beam that can form a real image upon reflection from a plane mirror is a convergent beam.

### Final Answer:
The incident beam is a **convergent beam**.

---