Answer: Option A. ->
:
Sub-parts : 1 Mark each
(i) A plane mirror is uniform in width from top, through center, till bottom.
(ii) A Convex mirror is one which feels thicker at middle than at the edges.
(iii) A Concave mirror is thicker at the edges as compared to the center.

Answer: Option A. ->
:
(a) Explanation: 2 Marks
(b) Explanation: 1 Mark
(a) Shiny objects are those that reflect most of the light that falls on them. Only those substances which have a smooth surface can be shiny. This is because smooth surfaces reflect light uniformly in a particular direction. Because of this, almost all of the light that falls on them get reflected collectively without any considerable loss.
Objects which are not shiny have rough surfaces. When light falls on these rough surfaces, the light get reflected in a random direction, leading to loss in intensity. Hence, such substances are not considered shiny.
(b) Light is made up of seven colours. When the sun shines after the rain and sunlight passes through suspended raindrops this white light from the sun splits into seven constituent colours "VIBGYOR”, which we see as rainbow

Answer: Option A. ->
:
Uses : 1 Mark each
(i) They are also put on corners of roads so that you can see any cars coming to avoid collisions.
(ii) Convex mirrors are also used in making lenses of sunglasses to help reflect the light of sun away from the eyes of the person wearing the sunglasses.
(iii) They are also used in telescopes.

Answer: Option A. ->
:
Uses : 1 Mark each
(i) A major application of concave mirrors is in headlights of the car.
(ii) They are used in magnifying glasses and telescopes.
(iii) Shaving mirrors are another example that makes use of concave mirrors because of their curved and reflective surface.

Answer: Option A. ->
:
Each correct match: 1 Mark
 
     Column I
        Column II
(a) A plane mirror
(v) The image is erect and of the same size as the object.
(b) A convex mirror
(ii) Can form the image of objects spread over a large area.
(c) A convex lens
(i) Used as a magnifying glass. 
(d) A concave mirror
(iii) Used by dentists to see an enlarged image of teeth. 
(e) A concave lens
​​​​​​​(vi) The image is erect and smaller in size than the object.

Answer: Option A. ->
:

(a) Explanation with reason: 3 Marks
(b) Solution: 2 Marks
(a) The mirrors commonly used for back and side mirrors are convex in nature. This is done to take advantage of the wider angle that can be reflected by a Convex mirror. A convex mirror, also known as converging mirror, is one which bulges at the middle and is thinner at the edges. While this captures a wider object field, it does so at the cost of image accuracy. The result is compression of the reflected image, which makes objects appear smaller and farther away than they really are.
 
The warning is mentioned in the mirrors so that the driver can accordingly make adjustments and take a well-calculated decision.
(b) The speed of car is 2 m/s which means the car is approaching the truck with a speed of 2 m per second.
The distance between the image of truck and truck will decrease at a double rate. This happens because for each meter the car moves, the mirror becomes closer to the object by 1 meter and also the image becomes 1 meter closer.
This is because the image of the truck will travel a distance twice the distance travelled by the car in equal time.
Hence, the image of the truck will appear to approach the driver with the speed of 2 × 2 = 4 m/s.
As the distance between the truck and car is 20m and the car is going back at a speed of 2m per second, the car will hit the truck in 10 seconds.

Answer: Option A. ->
:

Spherical Mirrors: 1 Mark
Types: 2 Marks
Properties: 2 Marks
The spherical mirror is a curved surface mirror which is a part of the hollow sphere.
Spherical mirrors are of two types:

1) Concave mirror

2) Convex mirror

Properties:
 
A concave mirror is a spherical mirror whose reflecting surface is curved inwards towards the source of light. Concave mirrors can produce both real and virtual images. They can be upright (if virtual) or inverted (if real), they can be behind the mirror (if virtual) or in front of the mirror (if real); they can also be enlarged, reduced, or the same size as the object. 

Convex mirror is a spherical mirror whose reflecting is curved outwards. Convex mirrors produce only virtual images.

Answer: Option D. -> Diminished
:
D
Plane mirrors always produce an image that is virtual, erect, laterally inverted and of the same size as the object. Also, the image distance from the mirror is always equal to the object distance from the mirror.

Answer: Option B. -> Convex mirror
:
B
Convex mirrors are commonly used as rear-view mirrors in vehicles because they give erect, virtual and diminished images of distant objects with a wider field of view. Thus, convex mirrors enable the driver to view a much larger area than would be possible with a plane mirror.

Answer: Option C. -> Concave
:
C

Concave mirrors are used in the headlights of a car.

When a bulb is placed at the focus of a concave reflector, the reflector collects the light rays and direct them into a powerful beam (in form of parallel rays) after reflection. Such beam can reach a large distance in dark and enable vision up to greater distances.