Courses
By Swati Singh
|
Updated on 11 Sep 2025, 17:35 IST
In Class 11 Physics (Ray Optics), the study of mirrors is a fundamental step toward understanding image formation. A concave mirror, also called a converging mirror, is a spherical mirror with its reflecting surface curved inward. These mirrors are extensively used in scientific instruments, telescopes, headlights, and shaving mirrors due to their ability to form both real and virtual images.
To master this concept, it is essential to understand ray diagrams, which graphically represent how light rays behave when incident on a concave mirror. These diagrams help visualize where an image will form, its size, and whether it will be real or virtual.
Before diving into ray diagrams, let us recall some fundamental terms:
Understanding these terms is crucial because each ray diagram depends on these reference points.
While infinite rays can be drawn to trace image formation, in practice, a few standard rules make diagrams simpler and more accurate:
Using these rules, we can draw accurate ray diagrams for any object position.
1. Object at Infinity
2. Object Beyond Centre of Curvature (C)
3. Object at Centre of Curvature (C)
JEE
NEET
Foundation JEE
Foundation NEET
CBSE
4. Object Between C and F
5. Object at Focus (F)
6. Object Between Focus (F) and Pole (P)
These six cases cover all possible positions of objects relative to a concave mirror.
Concave mirrors are not just theoretical concepts; they have practical importance:
Telescopes & Microscopes: Used in reflecting systems for clearer and magnified views.
Studying concave mirror ray diagrams strengthens conceptual clarity in optics. It builds the foundation for advanced topics like refraction, lenses, and wave optics in later chapters. It also develops problem-solving skills for competitive exams (NEET, JEE, Olympiads) where both numerical and conceptual questions appear.
The concave mirror ray diagram is one of the most important topics in Class 11 Physics. By learning the rules of reflection, practicing all six cases of image formation, and applying the mirror formula, students can confidently solve both theoretical and numerical problems. Understanding its applications in real life further builds appreciation for how physics principles shape technology.
In summary, concave mirrors demonstrate how simple reflective surfaces can form images ranging from tiny points to large magnified views, making them indispensable in both classrooms and practical life.
No courses found
A concave mirror is a spherical mirror whose reflecting surface is curved inward, resembling the inside of a sphere. It is also known as a converging mirror because it brings parallel rays of light to a single point (focus) after reflection.
The standard rules are:
A ray parallel to the principal axis passes through the focus after reflection.
A ray passing through the focus reflects parallel to the axis.
A ray passing through the centre of curvature retraces its path.
There are six main cases depending on the position of the object:
At infinity
Beyond the centre of curvature (C)
At centre of curvature (C)
Between C and focus (F)
At focus (F)
Concave mirrors are used in:
Car headlights and torches (to produce parallel beams).
Shaving/make-up mirrors (to get enlarged virtual images).
Solar furnaces (to concentrate sunlight).
Telescopes and microscopes (to focus light and magnify images).
A concave mirror forms a virtual, erect, and magnified image when the object is placed between the focus (F) and the pole (P).
They are called converging mirrors because rays of light parallel to the principal axis converge at a point (focus) after reflection.
When the object is at the centre of curvature (C), the image is formed at C itself, it is real, inverted, and of the same size as the object.
The maximum magnification occurs when the object is placed very close to the mirror (between F and P). In this case, the image is virtual, erect, and highly magnified.
