Science questions in short. [2 marks ]

The size of the eyes of nocturnal bird is large. Large eyes with a wider pupil, larger lens and increased retinal surface can collect more ambient light which help them to see the objects even at night easily.

Light is splitted into its constituent colours (7 colours) when it gets dispersed, e.g. rainbow formation is due to the dispersion of white light after passing through water droplets.

According to reflection properties of plane mirror, it forms same size, laterally inverted images of the object infront of them.

The correct diagrams are as below

The image of the child cannot be obtained on the screen because the image is not real. The images formed by plane mirror are virtual, so these virtual images cannot be seen on the screen.

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Since, when we are in the bright sunlight at that moment iris causes the pupil to become smaller, so that a little amount of light can enter the eye. Moreover, the rods of retina are also made to get adjusted in the same manner.
And when a person enters into dim light room, then iris takes sometime to increase the pupil diameter, due to which large amount of light enters the eye, so that's why when we enter into the room from bright sunlight outside, then we usually take sometime to see the objects in a dim room.

The unclear image of the mountains on the second day is probably due to wind blowing across the lake causing it to lose its calmness. When the lake is calm, the surface of the lake is smooth and regular reflection occurs, allowing a clear image of the mountains to be formed.
When the wind blows across the lake, the surface of the lake becomes rough and uneven causing a diffused reflection. Hence, the image formed of the mountains will be unclear and blurred.

In condition 1, eyes get insufficient amount of light. That's why, the pupil expands but in condition 2, eyes get large amount of light that's why pupil contract.

As we know that, ciliary muscles can contract and relax, because of it, this can change the shape of eye lens which results in change in its focal length. So, eye lens can make image of nearby objects and also far off objects on retina.

Yes, it is very true to say because the formation of image on the retina is conveyed to brain in the form of electrical impulses with the help of optical nerves. So, brain is able to perceive an erect image of object with the help of electrical impulses.

In people suffering from cataract, the eye lens becomes cloudy.
Cataract is treated by replacing the convex lens with a new artificial lens.

False, the laws of reflection holds for both regular and diffused reflection. In a diffused reflection, the reflecting surface being rough and uneven, the parallel beam of light is reflected in different directions and angles.

Due to reflection, we can see various objects. Since, we know that, all surfaces reflect light. So when light falls on them (any objects), it reflects the light. In this way, this reflected light enters our eyes and due to this, we can see the object.

The sandpaper has a rough surface causing light that is reflected on it to be scattered at different angles. The mirror however, allows regular reflection.
Sandpaper cannot produce any image, unlike the mirror due to diffused (irregular) reflection.

As Boojho is not in the range of reflecting surface rather, he is standing away from the mirror, so he cannot see himself in the mirror. But he can see the image of P which is in the reflecting area but not of Q and R

The diagram will be as follows

Laser light comes from a very small hole and the lens of the laser light is also very small, so the light will penetrate into one part of the eye and it can injure the retina, whereas the normal torch spreads out the light which does not cause any harm to our eyes.
So, the beam of laser light should not be used to perform an activity.

A kaleidoscope is an optical instrument with two or more reflecting surfaces tilted to each other at an angle.
It is used by designer of wallpapers and fabrics artists to get idea for new patterns.
An interesting feature of a kaleidoscope is that you will never see the same pattern again.
It is based on the principle of multiple reflections of light.

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There are two laws of reflection as below
(i) The angle of incidence is equal to the angle of reflection.
(ii) Incident ray, reflected ray and the normal drawn at the point of incidence to the reflecting surface, all lie in the same plane.

Differences between regular and diffused reflection are

Regular reflection	Diffused reflection
It is caused by the reflection from smooth and shiny surfaces.	It is caused by reflection from unpolished and rough surfaces.
Reflected rays are parallel to each other.	Reflected rays are not parallel to each other.

No, the diffused reflection does not mean the failure of the laws of reflection.

In the dark room, we cannot see objects because the objects are visible only when light from an object enters in our eyes.
We can see the objects outside the room, if there is light outside. If there is no light outside the room again, we cannot see the object.