Mention the name of an object which does not allow the light to pass through it.

2

(a)

You have 3 opaque strips with very small holes of different shapes as shown in figure. If you obtain an image of the sun on a wall through these holes, will the image formed by these holes be the same or different?

2

(a)

Shadow of flying aeroplane cannot be seen on the earth. Explain why.

2

(a)

Observe the picture given in figure. A sheet of some material is placed at position P, still the patch of light is obtained on the screen. What is the type of material of this sheet?

2

(a)

Mention the type of image is formed in pinhole camera.

2

(a)

In a complete dark room, we are not able to see our face. Why?

2

(a)

As we know that moon appears to be bright at night. Does it mean that it is an luminous object?

2

(a)

How do we see the objects around us?

2

(a)

What are shadows?

2

(a)

What property of light is responsible for the formation of shadows and pinhole images?

2

(a)

What do you understand by incandescent body?

2

(a)

Give two effects of light on plants.

2

(a)

What are the properties that are exhibited by light?

2

(a)

Why is the shadow of an aeroplane flying high in the sky not seen on the ground?

2

(a)

Rahul was studying at home in the evening. But due to improper power supply, he could not study properly.
(i) Why was Rahul able to study the print of book?
(ii) What is the role of light?

2

(a)

Suggest a situation where we obtain more than one shadow of an object at a time.

2

(a)

Using a pinhole camera, a student observes the image of two of his friends standing in sunlight wearing yellow and red shirt respectively. What will be the colours of the shirts in the image?

2

(a)

One day, Richa saw a shadow of bird on the wall of her room. After some time, it dissappears, she surprised where the bird has gone. Her brother explains that it was nothing as it was the shadow of his hand.
(a) Mention the values that Richa's brother reflect here.
(b) Shadow can mislead you. Justify the statement.

2

(a)

Three torches A, Band C shown in figure are switched ON one by one. The light from which of the torches will not form a shadow of the ball on the screen?

2

(a)

Show an experiment which proves that light always travels in a straight line.

2

(a)