Mirrors and Image Formation
Curved mirrors form real or virtual images.
About this topic
Curved mirrors form images by reflection. A concave mirror converges light and can produce real inverted images or magnified virtual images when the object is inside the focal length, as in shaving mirrors. A convex mirror diverges light and always gives a smaller, upright, virtual image over a wider field of view.
The focal length of a spherical mirror is half its radius of curvature, f = R/2, and the mirror equation 1/f = 1/u + 1/v is the same as for lenses. Concave mirrors are used in car headlights, torches, dental mirrors and reflecting telescopes, while convex ones are used for shop security and passenger-side car mirrors, where the label warns that objects are closer than they appear.
Worked example: a concave mirror with f = 20 cm and an object at 60 cm gives 1/v = 1/20 − 1/60 = 2/60, so v = 30 cm, a real inverted image with magnification 0.5. With the object at 10 cm instead, 1/v = 1/20 − 1/10 = −1/20, so v = −20 cm: a virtual, upright, magnified image behind the mirror, twice the size.
Solar cookers and solar power towers focus sunlight with curved mirrors. A misconception is that virtual images are unreal tricks; they simply cannot be projected onto a screen, though your eye sees them perfectly well.
Key ideas
- Concave mirrors can focus
- Convex mirrors widen the view
- Ray diagrams find images
Quick check
Use cases: where Mirrors and Image Formation helps
- Homework: review the key idea behind Mirrors and Image Formation before you start a problem set.
- Exam revision: use the quick check to test whether you can recall Mirrors and Image Formation without notes.
- Visual learning: play with the interactive lab to see how Mirrors and Image Formation changes when you adjust its inputs.
- Teaching a friend: explain Mirrors and Image Formation in your own words, then compare your version with the key ideas.
The same laws describe car crashes, sports, satellites and everyday machines.
Frequently asked questions
What is Mirrors and Image Formation?
Curved mirrors form real or virtual images.
What will I learn in Mirrors and Image Formation?
Concave mirrors can focus. Convex mirrors widen the view. Ray diagrams find images.
Is Mirrors and Image Formation part of Physics?
Yes. It is one of 150 Physics topics on LearnViz HighSchoolEdu, with 3 key ideas, a live animation and a quick check.
Does the Mirrors and Image Formation lab work on a phone or tablet?
Yes. The animation resizes to fit your screen and supports touch, so you can drag, tap and slide with your finger.
How should I study Mirrors and Image Formation?
Read the summary and key ideas first, play with the interactive lab to see the idea in motion, then answer the quick check. If you get a question wrong, go back to the key idea it tests.
Do I need an account, and is my progress saved?
No account is needed. Marking a topic as learned is saved in your own browser, so it stays on that device and is not sent to a server.