Boojho planned an activity to observe an object A through pipes as shown in figure so that he could see objects which he could not directly see.

(a) Mention how many mirrors should he use to see the objects.
(b) Indicate the positions of the mirrors in the figure.
(c) State what must be the angle w.r.t. the incident light at which he should place the mirrors.
(d) Indicate the direction of rays in the figure.
(e) If any of the mirrors is removed, will he be able to see the objects?

5

(a)

Explain the process which enables us to perceive motion in a cartoon film.

5

(a)

A man stands 10m in front of a large plane mirror. So, how far must he walk before he is 5 m away from his image?

5

(a)

How is the phenomenon of reflection used in making a kaleidoscope? What are the applications of a kaleidoscope?

5

(a)

Aditya visited a lake on two days. On the first day, the reflection of the surrounding mountains could be seen clearly in water of the lake. On the second day, he was not able to see the reflection of the mountains clearly. Give one possible reason for this phenomenon and explain your answer clearly.

5

(a)

Explain the reason for the following statement. We usually take some time to see the objects in a dim light room, when we enter into the room from bright sunlight outside.

5

(a)

Describe an activity to show that the incident ray, the reflected ray and the normal at the point of incidence, all lie in the same plane.

5

(a)

Describe the construction of a kaleidoscope.

5

(a)

Write down the names of parts of the eye in the blank spaces shown in fig. below.

5

(a)

How can you take care of the eyes?

5

(a)