What is a concave mirror do?
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Concave Mirrors
Definition
A concave mirror, also known as a converging mirror, is a mirror that has a reflective surface that curves inward, resembling a portion of the interior of a sphere. This curvature causes light rays that are parallel to the mirror's principal axis to converge at a focal point after reflection.
Properties of Concave Mirrors
- Focal Point: The point where parallel rays of light meet after being reflected is called the focal point.
- Principal Axis: An imaginary line that passes through the center of the mirror and the focal point.
- Centre of Curvature: The center of the sphere from which the concave mirror is a segment.
- Vertex: The point where the mirror's surface and the principal axis intersect.
- Focal Length: The distance between the focal point and the vertex.
Image Formation by Concave Mirrors
Concave mirrors form images that can be either real or virtual, depending on the position of the object relative to the focal point and the mirror. Image characteristics such as size, orientation, and type vary as the object moves closer to or farther from the mirror.
Uses of Concave Mirrors
- Shaving and Make-up Mirrors: Provide magnified, upright images for better view.
- Reflecting Telescopes: Used to focus light to create clear images of distant objects.
- Headlights: To focus light beams into powerful, parallel rays for illumination.
- Solar Furnaces: Harness solar energy by focusing sunlight to a specific point, creating high temperatures.
Table of Image Characteristics in Concave Mirrors
| Object Position | Image Type | Image Position | Image Size | Image Orientation |
|---|---|---|---|---|
| At infinity | Real and Inverted | At the focus | Highly Diminished | Inverted |
| Between infinity and center of curvature | Real and Inverted | Between focus and center of curvature | Diminished | Inverted |
| At center of curvature | Real and Inverted | At the center of curvature | Same Size | Inverted |
| Between center of curvature and focus | Real and Inverted | Beyond center of curvature | Enlarged | Inverted |
| At the focus | Not Formed | --- | --- | --- |
| Between focus and mirror | Virtual and Upright | Behind the mirror | Enlarged | Upright |