PAGE: SC – RLT – A – 02
f

r
2
The required relation is :
2.
CONVEX MIRROR has a virtual principal focus.
3.
Position of the object
:
At the centre of curvature ( C ) .
4.
Position of the object
:
Between the FOCUS ( F )
and the POLE ( P ) .
5.
Position of the object
:
Between the FOCUS ( F )
and the POLE ( P ) .
6.
Position of the object
:
Between the FOCUS ( F )
and the POLE ( P ) .
7.
Position of the image
:
At INFINITY .
8.
NO, the person will not get the required image.
9.
(i)
10.
Position of the object
:
Between the FOCUS ( F )
and the POLE ( P ) .
11.
Position of the object
:
Between the FOCUS ( F )
and the POLE ( P ) .
12.
NEGATIVE sign has been given to the focal length of a concave mirror according to the sign convention.
13.
CONVEX mirror has positive focal length.
14.
The mirror is CONVEX.
15.
YES, the image can be obtained on a screen.
16.
CONVEX mirror has the wider field of view.
17.
CONVEX mirror always produces a virtual, erect and diminished image of an object.
18.
The person should use CONCAVE MIRROR.
19.
CONVEX mirror is used in vehicles to see the traffic on the rear side.
20.
A driver prefers to use a convex mirror as a back view mirror in an automobile due to the following reasons :
CONCAVE MIRROR
( ii )
where
f = focal length
r = radius of curvature
1.
PLANE MIRROR.
a.
A convex mirror always produces an erect image.
b.
The surface of a convex mirror is curved outwards which provides a wider field of view.
21.
Position of the image
22.
(DIAGRAM)
:
at a point 15 cm behind the mirror ( at the virtual FOCUS of the mirror )
In a convex mirror, a light ray parallel to the principal axis appears to be coming from the virtual focus of the mirror after
reflection.
Therefore, a beam of parallel light rays appear to be diverging from the virtual focus.
23.
(DIAGRAM)
In a concave mirror, a light ray parallel to the principal axis passes through the focus of the mirror after reflection.
Therefore, a beam of parallel light rays converge at the focus.
24.
25.
Uses of Concave Mirrors : –
1.
as reflectors in the headlights of cars.
2.
as the Dentist’s mirror to focus light on the tooth to be examined.
Uses of Convex Mirrors : –
3.
as rear-view mirrors or side-mirror on cars trucks and buses.
4.
as vigilance-mirrors in big shops and stores.
(DIAGRAM)
A’B’ is the image of AB.
Characteristics of the image are :—
26.
Nature :
Virtual and Erect
Position :
Behind the mirror
Size :
Magnified
(DIAGRAM)
A’B’ is the image of AB.
Characteristics of the image are :—
27.
Nature :
Real and Inverted
Position :
Between
Size :
Diminished
the centre of curvature ( C ) and
the focus ( F ) .
Each mirror is brought near the face, one by one
The mirror that forms an image of EQUAL size is the PLANE mirror.
The mirror that forms a MAGNIFIED and erect image is the CONCAVE mirror.
The mirror that forms a DIMINISHED and erect image is the CONVEX mirror.
28.
The shapes of the three parts of the mirror are :—
Portion
Top
Middle
Bottom
Shape of the mirror
Buldged out
Curved in
Plane
Type of mirror
Convex mirror
Concave mirror
Plane mirror