Reflection of Light
Q1. What is reflection of light?
A. The bouncing back of light rays when they strike a smooth surface like a mirror.
Q2. State the two laws of reflection.
A. (1) The angle of incidence is equal to the angle of reflection. (2) The incident ray, reflected ray, and the normal lie in the same plane.
Q3. What is the incident ray?
A. The ray of light that falls on a surface.
Q4. What is the reflected ray?
A. The ray of light that bounces off the reflecting surface.
Q5. What is the normal in reflection?
A. A line perpendicular to the reflecting surface at the point of incidence.
Q6. What is the angle of incidence?
A. The angle between the incident ray and the normal.
Q7. What is the angle of reflection?
A. The angle between the reflected ray and the normal.
Q8. Name two types of reflection.
A. Regular reflection and diffuse reflection.
Q9. What is regular reflection?
A. Reflection from a smooth surface where reflected rays are parallel, forming clear images.
Q10. What is diffuse reflection?
A. Reflection from a rough surface where reflected rays are scattered, and no clear image is formed.
Q11. Give an example of regular reflection.
A. Reflection from a plane mirror.
Q12. Give an example of diffuse reflection.
A. Reflection from a wall.
Q13. What is lateral inversion?
A. The reversal of image from left to right in a plane mirror.
Q14. What is the image distance in a plane mirror compared to the object distance?
A. They are equal.
Q15. What is the focal length of a plane mirror?
A. Infinite, because it does not converge or diverge light.
Q16. What is a concave mirror?
A. A spherical mirror whose inner reflecting surface is curved inward.
Q17. What is a convex mirror?
A. A spherical mirror whose outer reflecting surface is curved outward.
Q18. What is the principal axis of a mirror?
A. The straight line passing through the pole and center of curvature of the mirror.
Q19. What is the focal point of a mirror?
A. The point where parallel rays of light converge (concave) or appear to diverge from (convex) after reflection.
Q20. State the mirror formula.
A. 1/f = 1/u + 1/v, where f is focal length, u is object distance, and v is image distance.
Q21. What is magnification?
A. The ratio of image height to object height, given by M = h'/h = -v/u.
Q22. Give one use of concave mirrors.
A. Used in shaving mirrors to get an enlarged image.
Q23. Give one use of convex mirrors.
A. Used as rear-view mirrors in vehicles.
Q24. What kind of image is formed by a plane mirror?
A. Virtual, erect, and same size as the object.
Q25. What kind of image is formed by a concave mirror when the object is beyond the center of curvature?
A. Real, inverted, and smaller than the object.
Q26. What is the center of curvature?
A. The center of the sphere of which the mirror is a part.
Q27. What is the pole of a mirror?
A. The center point of the mirror's surface.
Q28. What happens when the object is at the focal point of a concave mirror?
A. The reflected rays become parallel, and the image is formed at infinity.
Q29. What is multiple reflection?
A. The repeated reflection of light between two or more mirrors.
Q30. Give one example of multiple reflection in daily life.
A. In a periscope or kaleidoscope.