🔮 Exploring Mirrors and Number of Images 🔮
1. Group Activity
Students will perform the following demonstrations to understand reflection and number of images formed by mirrors:
- 🪞 Plane Mirror Observation – Each student comes forward and observes his/her image in a single plane mirror.
- 🔁 Two Mirrors at Different Angles – Two mirrors are placed at angles of 180°, 90°, and less than 90°.
- 🔭 Curved Mirrors – Demonstrate how concave and convex mirrors form images differently.
Students will share what they observe – the number, size, and orientation of the images.
2. Relation Between Angle and Number of Images
The number of images (n) formed by two plane mirrors inclined at an angle θ is given by:
n = (360° / θ) – 1
- At 180° → Only 1 image is formed.
- At 90° → 3 images are formed.
- As the angle decreases, the number of images increases.
- When mirrors are parallel, multiple reflections appear, forming many images.
3. Moral Connection
🌟 The more we open our angle to learning, the more reflections of knowledge we gain.
💡 Like mirrors, stay clear and true — reflect only goodness!
4. Question & Answer Session
Q1. What is the relation between the number of images and the angle between two mirrors?
n = (360° / θ) – 1
Q2. How many images are formed when two mirrors are placed at 180°?
One image
Q3. How many images are formed when mirrors are placed at 90°?
Three images
Q4. What happens to the number of images when the angle between mirrors decreases?
The number of images increases.
Q5. What happens when mirrors are kept parallel to each other?
Many multiple images are seen due to repeated reflections.
Q6. What type of image is formed by a plane mirror?
Virtual and erect image
Q7. Which mirror forms a real and inverted image?
Concave mirror
Q8. Which mirror always forms a virtual, erect, and diminished image?
Convex mirror
Q9. What is the special property of a plane mirror regarding image size?
Image is of the same size as the object.
Q10. What is the practical use of multiple reflections?
Used in kaleidoscopes and optical instruments.