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Correct answer is (c) Vacuum

Correct answer is (c) Infinity

1. Object and its reflection result in formation of images.

2. Reflections taking place from highly polished metals, mirrors, still water etc, form clear images.

3. Reflections taking place from wooden surface, flower, book form dull, blurred images.

4. The difference in reflections is caused by the surface of the object.

5. Regular reflections have smooth, polished surfaces, hence, image is clear.

6. Diffused reflections have hard, rough surfaces, hence, image is dull.

1. The left and right sides of the original object appear to be exchanged in the mirror image. 

2. The image is as far behind the mirror as the object is in front of it.

3. The size of the image is the same as that of the object.

MIRRORS

(1) The reflecting surface of the concave mirror bugles inwards. But the reflecting surface of the convex mirror bugles outwards.
(2) A concave mirror produces real and inverted images (except when the object is placed between the pole and focus. When the object is placed between F and P, concave mirror produces virtual and erect image). But the convex mirror always produces virtual and erect images.
(3) The image formed by the concave mirror may be enlarged or diminished, according to the position of the object. The image formed by the convex mirror will be always diminished. 
 

LENSES

Convex lenses are curved outward and they cause light that goes through it to converge or concentrate on one point. Think of a magnifying glass that is used to burn something. The light that goes through it concentrates on a point so you can burn things. Concave lenses are curved inward and when the light goes through it diverges or spreads out. Think of a flashlight. The light comes from a small bulb goes through it and spreads out to a bigger beam on the other side.

The correct option is A) yellow.

Iris, the part of our eye, contains pigment and gives the eye its distinctive color. Iris also helps in controlling the size of the pupil by constricting and dilating it, thus reducing and increasing the amount of light entering the eye.

C. the lens becomes thicker or thinner 

The shape of the lens is changed by ciliary muscles so that the image forms at a sharp focus at the retina. The lens becomes thicker to focus at near objects and becomes thinner to focus at distant objects.

A. increases gradually 

If the angle between 2 plane mirrors is decreased, the number of images of an object placed in between will increase gradually.

The relationship between no. of images and angle of mirror is 

Images = (360 degrees/ angle between the mirrors) – 1

Blind spot is the point in human eye where the image is not visible. This is because there are no photo receptors, i.e., rods and cones present in the optical disk.

The range of vision of a normal human eye is from 25cm to infinity. The minimum distance for an object to be viewed clearly for a normal human eye is 25cm and the view may extend to infinity.

Jugnu, firefly.

Convex mirror. Convex mirrors can form images of objects spread over a large area. So these help the drivers to see the traffic of a large area behind them.

Retina is the light sensitive part of the eye where image of an object is formed.

Between the pole and the focal length.

1. It is used as a reflector in torches, light houses, head lights of vehicles, etc., as it diverges the ray of light.

2. A dentist uses a concave mirror to obtain a magnified image of the teeth of the patient.

The correct option is D) white.

1. A source of light 

2. A screen 

3. An opaque object

The image formed in the mirror is ‘laterally inverted’ i.e. right side appears as left side and left side appears as right side.

Sunlight reflected from the surface of the moon reaching us, in which we see the moon is called the moonlight.

Light ray travels in a straight line.

Natural substances, materials which emit light are called natural sources of light.

Property of light travelling in a straight line is linear propagation of light.

The correct option is D) i,ii,iii.

Convex mirrors are used as rearview mirrors in vehicles and safety mirrors at curved roads.

(a) seven colours

1. True

2. False - When light travels from one medium to another, it suffers deviation.

3. True

4. False - The image formed is real, inverted and same size of the object.

5. True

Correct answer is (a) vacuum

When a beam of light falls on a rough surface it is turned back in different directions. It is called scattering of light.

The incident ray reflected ray and normal to the surface are present in the same plane and incident, reflected rays are on either side of normal. This is the second law of reflection.

The distance of the object from the mirror is called object distance.

The distance of the object from the mirror is equal to the distance of image from the mirror.

The angle of incidence is always equal to angle of reflection. 

Angle of incidence = Angle of reflection This is the first law of reflection.

a) More rods and few cones

The shadow formed will be dark and of the shape of the flower along with the stalk.

We see rainbow colours on the paper.

yes, we can. Light gets seperated into seven colour. From this we learn that white light contains seven colours.

Air around us is transparent but when thick smoke, thick clouds, etc. are present in the air it does not remain transparent.

The colour of light will not affect the shadow, because shadow is the dark patch formed when an object obstructs the path of light and hence no light reaches in the shadow region.

Characteristics of an image formed by a pinhole camera are as follows:

1. It is inverted/upside down.

2. It can be obtained on a screen – real image.