Science 2 Marks Questions

When an image cannot be obtained on a screen, it is called a virtual image.

The image formed by a plane mirror is virtual, because the image cannot be obtained on a screen when placed either in front of the mirror or behind it.

The image formed by a plane mirror is erect, laterally inverted, and of the same size as that of the object. The left side of the object appears on the right side of the image. Also, the distance of the image from the plane mirror is same as the distance between the plane mirror and the object.

If on decreasing the distance between the object and lens, the size of the image increases, then the nature of the lens is convex type. No, if the distance between object and lens is less than the focal length of the lens, then it will form a virtual image which cannot be obtained on a screen.

No, he will not observe band of seven colours because laser light consists of monochromatic light of a single colour. However, seven colours of bands are observed, when a white light is passed through a prism and dispersion takes place.

1. Real image: Real image are those images that can be captured on a screen are known as real images. For example, in a camera, images are real and can be captured on the negative, which acts as a screen.
2. Virtual image: The image formed by a plane mirror cannot be captured on a screen, and is called a virtual image.

An image which cannot be obtained on a screen is called a virtual image. A virtual image can be formed by a plane mirror, convex mirror, concave mirror, convex lens and concave lens. Polished Metallic surface or liquid surface such as lakes or water bodies can also form a virtual image.

Images in a mirror are located at the same distance behind the mirror as the object in front of it is mainly used in interior decoration and in architecture to make rooms appear brighter and bigger. Moreover, placing a mirror near lights, chandeliers and table lamps reflects the light over a larger area, and makes the room appear brighter. Images that cannot be captured on a screen are called virtual images.

In case of convex lens, when we move the object away from the lens, the size of image decreases and ultimately, when object is at infinite distance a point image is formed at the focus of lens.

Image formed by a plane mirror is:

1. is erect.
2. It is virtual and is of the same size as the object.
3. The image is at the same distance behind the mirror as the object is in front of it.

When an image is formed by the mirror in such a way that the left side of image is object’s right side and right side of image is object’s left side. So, this process of change in the sides of the object as well as of image is known as lateral inversion.

Since, the extent of reflection depends upon the shine and smoothness of the surface. So, greater the shining and smoothness of the surface, greater will be the reflection. So, this is a reason why we require a shiny surface for reflection.

A rainbow is formed by the refraction and reflection of the sun's rays through raindrops. When it is raining in one part of the sky and sunny in another, a rainbow appears. The centre of the rainbows arc is always directed away from the sun.

In case of mirror, the reflected rays of light are parallel and reach our eyes. That's why we can see objects through mirror or any shining surface. Walls surface are rough and reflection of light is diffused. Due to which walls do not act as mirror.

1. In an opaque spherical surface, the silvered surface acts as a mirror. So, a concave mirror will have its concave side silvered, while a convex mirror will have its convex side silvered.
2. For a transparent spherical surface, if the concave surface is silvered and later coated with red oxide, then the mirror acts as a convex mirror. Also, if the convex surface is silvered and later coated with red oxide, then it acts as a concave mirror.

We can identify the mirrors by forming images of an object which are given as below:

1. Plane mirror In case of plane mirror, image will be virtual, erect and of same size as that of object.
2. Concave mirror In case of concave mirror, image may be real or virtual, inverted or erect and magnified or diminished depending upon the position of object.
3. Convex mirror In case of convex mirror, image formed will always be virtual, erect and diminished in spite of the position of object.

A piece of transparent material bound by curved surfaces. There are two types of lens concave lens and convex lens. Convex lens is thick at the centre and thinner at edges, it is called converging lens concave lens is thin at the center and thicker at edge, it is called diverging lens.

The characteristics of image formed by a concave mirror are:

1. The image formed by a concave mirror is not always the same size as the object. It can be either larger or smaller depending on the distance of the object to the mirror.
2. The image formed by a concave mirror is inverted when the object is kept far from the mirror. So, when it is brought very close to the concave mirror, then an erect and enlarged image is formed.

In case of mirror, the image formed by it is laterally inverted, i.e. left seems to be right and right seems to be left. So, in ambulance there is emergency for patients to reach hospital and by viewing in rear mirror, it can be easily identified of a vehicle and everyone give him a way.

Concave mirror is called a converging mirror because parallel rays of light fall on the mirror they converge at a point called focus. Convex mirror is called a diverging mirror because parallel rays of light fall on it they diverge after reflection.

There are two types of lenses:

1. The lens which is thinner in the middle than at the edges is called a concave lens while the lens.
2. Which is thicker in the middle than at the edges is called a convex lens.

Such types of lens which always forms virtual, erect and smaller image in spite of the different positions of an object is called concave lens.

Spherical mirror have curved reflecting surfaces and are also called curved mirrors. These mirrors are made from a hollow sphere. There are two types of curved surfaces at each hemisphere. The inner curved surface is termed as concave, while the outer is called convex. Spherical mirrors are different from plane mirrors due to their reflecting surface.

1. Convex mirror is a mirror which is used as a rearview mirror. It is used to get a wide view of traffic behind.
2. The values exhibit by Namit here is courtesy concerned for other, sympathy, knowledgeable.

The nature of image formed in a concave mirror depends on the portion of the object in front of the mirror. If the object is very close to the mirror the image is virtual, erect & magnified. As the distance increases image becomes real, inverted & its size keeps changing.

1. The image which can be formed on the screen is real image.
2. The image which cannot be formed on the screen is virtual image.

If the concave reflecting surface of a torch get rusted, it will produce diffused beam of light with lower intensity, the objects will not be clearly visible in this diffused and lower intensity of light.

The two laws of reflection are:

1. Angle of incidence is equal to angle of reflection.
2. Incident reflected ray & the normal lie on the same plane.

If a shopkeeper wanted to fix a mirror which will give him maximum view of his shop, he should use a convex mirror. As a convex mirror can form images of objects spread over a large area, i.e. it can give a wider field of view.

Convex mirror is used as a side mirror in a scooter because it can form diminished images of objects spread over a larger area. So, this helps the driver to have a wide field of view of traffic.

On identifying the letters of newspaper, we can differentiate the two types of lenses. If image is large or magnified, then the lens is a convex lens and if the image is smaller or diminished in size for all the positions of object, then the lens is concave.

An erect and enlarged image of an object can be formed by either concave mirror or convex lens if an object is placed upside down between the focus and centre of curvature of concave mirror or convex lens.

Mirror maze is created based on the principle of reflection in plane mirrors. The maze has several plane mirrors placed at fixed angles to each other. When a person enters a mirror maze, he finds several images of himself and several passages. There is only one passage that is real, while all the others are all just images.