Light

When the image is erect and of same size as object then it is a plane mirror so Boojho has plane mirror

When the image is erect and of small size than object then it is a convex mirror so Paheli has a convex mirror

Image formed by a plane mirror and convex mirror is always virtual .

image formed by concave mirror is real always but when object is placed very close to concave mirror, image is virtual.

The image formed by the mirror is at same distance behind the mirror as object is in front of it, now

If distance of object from mirror = 0.5 m

Then distance of image from mirror = 0.5 m

So, distance between object and mirror = 0.5 m+ 0.5m = 1m

Image formed by convex mirror or concave lens is always smaller in size than the object.

Image formed by concave mirror or convex lens is always larger in size than the object i.e Enlarged image.

Rainbow can be seen in the sky only when the sun is behind us because the rainbow reflects the light of the sun , and reflection does not take place in the side of object, it takes place in opposite side.

Generally, a concave mirror forms an inverted image of the object, but when the object is placed very closed to concave mirror the image formed is Erect and enlarged.

concave mirror forms - inverted image

Convex mirror forms - erect image

Concave lens forms - erect image

Convex lens forms - inverted image

A convex lens forms erect and magnified image only when object is close to lens otherwise it forms inverted image

A concave lens forms erect and smaller image than object always.

This is a concave lens since a concave lens forms always erect, virtual and smaller image than object kept at any position in front of mirror.

(a) concave

Inner surface of steel spoon acts as concave mirror because it forms real, inverted and smaller size image than object.

It also forms virtual, erect and enlarged image when object is very closed to spoon.

(b) plane

Flat plate acts as plane mirror because it forms virtual, erect and same size image as object

its neither convex nor concave.

(c) convex

It is because the outer surface of round bottom steel bowl forms virtual, erect and small size image than object like convex mirror.

(d) concave

Reflectors of torches are concave in shape and acts as concave mirror to obtain parallel beam of light and good intensity.

(a) FALSE

a concave lens forms smaller and erect image always.

(b) FALSE

A convex lens forms virtual image when object is very close to lens otherwise it forms Real image.

(c) TRUE

In the image formed by concave mirror left side seems to be right side and right side looks like left side of object.

(d) FALSE

An object can be seen if it emits light but it can also be seen when it reflects the light falling on it.

Convex mirrors are used as side mirror in the scooters.

it is because a convex mirror can form images of object spread over large area , so the images help the driver to see traffic behind them and also prevents them from any accident or damage to vehicle.

Box A - covex lens

Box B - concave lens

in given figure, nature of lens A is convex as the convex lens generally converges the light rays falling on it i.e it bends the rays inwards. Convex lens is also called 'converging lens’.

nature of lens B is concave as the concave lens generally diverges the light rays falling on it i.e it bends the rays outwards. Concave lens is also called 'Diverging lens’.

No, he will not be able observe the band of seven colours because laser light is made up of only a single colour.

he would have observed band of seven colours if white light was made to fall on prism , because white light is actually made up of seven colors.

when white light is passed through a prism then if forms colors as the sequence of VIBGYOR starting from down and then going up.

when white light is passed through an inverted prism then if forms colors as the sequence of VIBGYOR starting from up and then going down

The side mirror of a scooter is convex because it can form images of object spread over large area , and helps the driver to see traffic behind them.

If convex mirror is replaced by plane mirror then he will not be able to see large area behind him due to which he may not drive properly , it may also cause damage to his vehicle or an accident.

if the concave reflecting surface of a torch gets rusted ,it will not produce clear beam of light and it will produce light with lower brightness, so the object will also be not clearly visible in lower brightness or light.

Erect and enlarged image can be formed by concave mirror or convex lens but the image formed is virtual ( image that cannot be obtained on screen)

Real image (image that can be obtained on screen) is formed if object is placed upside down between focus and centre of curvature of concave mirror or convex lens.

without touching we can identify two different lenses by looking at the size of the letters of newspaper just below the lenses.

If the image of the letters is larger then it is a convex lens because convex lens produces enlarged image .

If the image of letters is smaller than the letters then it is concave lens because concave lens produces diminished image.

The shopkeeper should use a convex mirror if he wants to get maximum view of his shop because convex mirror forms images of object spread over wide area / large area which satisfies his wish.

in convex lens if size of the image formed on a screen is decreasing on moving the object, then object is moving in a direction away from then lens.

If object is moved towards the convex lens then size of image formed on screen increases.

A real image is formed by concave mirror or convex lens.

in first possibleway we can use a concave mirror and a screen , as concave mirror forms a real image only when object is at a distance to it, so concave mirror will produce real image of distant tree on the screen.

In second possible way we can use a convex lens and a screen. as convex lens forms a real image only when object is at a distance to it, so convex lens will produce real image of distant tree on the screen.

if on decreasing the distance between object and lens , the size of image increases then it is a convex type lens (converging lens)

If we keep on decreasing the distance between the object and the lens, we will not be able to obtain the image on the screen because when object is placed very closed to the convex lens ,the image formed is virtual.

Virtual images cant be obtained on screen.

We can identify the mirrors by forming image of an object by those mirrors

I) if the image formed of the object by the mirror is virtual, erect and of same size as object then the mirror is plane mirror.

II) if the image formed of the object by the mirror is virtual, erect and of small size than object then it is a convex mirror

III) when the object is at distance and image formed is real and inverted and if object is very close to lens, the image formed is virtual and erect then the mirror is concave mirror.