Question

12. What is the cause of refraction of light?
13. Which lens is used as a magnifying glass?
14. What is an optically denser medium of light?
15. What is the difference between reflection and refraction?
16. If a ray of light traveling in air is incident on the water surface obliquely, Draw a ray diagram and she
the change in its path in water?
17. Define refractive index in terms of a speed of light in two media. What is the unit of refractive index?
18. A ray of light strikes the mirror at 15°, what is the angle of reflection?
19. What is refractive index of air? Why the refractive index of other medium is taken with respected to
air?
20. Distinguish between real and virtual images?
21. For what position of an object, a virtual image is formed by a convex lens? Give ray diagram?
22. Find the position and nature of image formed in a concave mirror for the following position of an
object
(a) At infinity
(b) Beyond C.
23. An object is placed at a distance of 10cm from convex mirror of focal length 15cm; find the position and
nature of image?
24. A thin lens has a focal length of -25cm. What is the power of the lens? Is it convex or concave?
25. Calculate the distance at which an object should be place in front of convex lens of focal length 10cm to
obtain an image double its size?
26. Why a mirror does has one principal focus while a lens has two principal foci?​

Answer 1

Answer:

Light refracts whenever it travels at an angle into a substance with a different refractive index (optical density). This change of direction is caused by a change in speed. ... When light travels from air into water, it slows down, causing it to change direction slightly. This change of direction is called refraction