Reflection of Light Science - Reflection of Light

In a periscope, the mirrors are ………….. .

In a kaleidoscope, the mirrors are inclined to each other at ……. .

If the angle of incidence is 20°, the angle made by the reflected ray with the normal to the surface must be ……… .

If the angle of incidence is 40°, the angle made by the reflected ray with the surface of the plane mirror must be ……. .

If the angle made by the incident ray with the surface of a plane mirror is 30°, the angle of reflection must be …….. .

In a periscope, the angle between the incident ray and the normal to the mirror is 30°.

The sense of vision is the most important among our five senses.

See Fig. In terms of O, what are the angles (i) AON (ii) BON (iii) AOB (iv) BOQ?

If the angle between the plane mirror and the incident ray is 20°, what is the angle between the reflected ray
and the plane mirror?

What is irregular reflection of light?

What is regular reflection of light?

What is the angle of reflection?
OR
Define angle of reflection.

How do we see the image of the moon in water?

What type of image do we see in a mirror? What happens to the left and right sides?

How do you see if the barber m a saloon has cut the hair on your neck properly or not?

Figures (a) and (b) show three parallel rays, shown in grey, incident on smooth and rough surfaces. The reflected rays drawn using laws of reflection are shown in red.
1. Rays reflected from which surface are parallel to one another?
2. What conclusion can you draw from the figure?

What will happen when a light ray is incident perpendicular to the mirror?

Periscope:

Kaleidoscope:

Material:
Torch light, mirror, a stand for hanging the mirror, black paper, comb, white paper, drawing board.
Activity :
1. Fit a white paper tightly over a table or drawing board.
2. Leaving out some portion in the middle of the comb, cover the rest with black paper so that light can only pass through the open central portion.
3. Hold the comb perpendicular to the white paper and throw torch light on its central portion.
4. Adjust the comb and torch so as to get light rays on the white paper. Now keep a mirror in the path of this ray of light as shown in the figure.
5. What do you observe?

What did you feel when it was turned on again?

Could you see the objects in the room clearly when the light was switched off?

Draw a figure showing the following:
(a) Incident ray
(b) Normal
(c) Angle of incidence
(d) Angle of reflection
(e) Point of incidence
(f) Reflected ray.

Draw a figure describing the following: The reflecting surfaces of two mirrors make an angle of 90° with each other. If a ray incident on one mirror has an angle of incidence of 30°, draw the ray reflected from the second mirror. What will be its angle of reflection?

Draw a figure describing the following: The reflecting surfaces of two mirrors make an angle of 90° with each other. If a ray incident on one mirror has an angle of incidence of 30°, draw the ray reflected from the second mirror. What will be its angle of reflection?

Plane mirror, Plywood, Wood, Rough tile.

Explain the difference between regular and irregular reflection of light.

Swara and Yash were looking in a water-filled vessel. They could see their images clearly in the still water. At that instant, Yash threw a stone in the water. Now their images were blurred. Swara could not understand the reason for the blurring of the images.
Explain the reason for blurring of the images to Swara by answering the following
(1)Is there a relation between the reflection of light and the blurring of the images?
(2)Which types of reflection of light can you notice from this?
(3)Are the laws of reflection followed in these types of reflection?