Question

Shyam participated in a group discussion in his interschool competition on
the practical application of light and was very happy to won the award for
his school. On that very evening, his father celebrated the day with a
family dinner. At a particular moment, Shyam observed in a curve plate,
the image of a person’s mobile sitting on his back side. Person’s mobile
was fell off which the person didn’t know about it. Shyam went to the
person and informed about this. The person was thankful to Shyam.
19 (i) From which side of the plate Shyam observed this incident?

a) Outward curve
b) Inward curve
c) Not curved
d) Straight

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19 (ii) The part of the curve plate was acting like which type of mirror?

a) Convex mirror
b) Concave mirror
c) Plane mirror
d) Parabolic mirror

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19 (iii) State the nature and size of image formed by this mirror.

a) Virtual, erect and diminished
b) Real , inverted and small
c) Virtual, erect and highly enlarged
d) Real, inverted and highly enlarged

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19 (iv) An object is placed at a large distance in front of a convex mirror of
radius of curvature 40cm. How far is the image behind the mirror?
a) 20 cm
b) 30 cm
c) 40 cm
d) 50 cm

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19 (v) An object is placed at a large distance in front of a convex mirror and all
ray are parallel to principal axis than size of image would be observed will
be:
a) Point size
b) Highly Enlarged
c) No image will form
d) No intersection occur

Answer 1

1 a

2 b

3 c

4 a

5 c ya answer hon gay check ker legay ga

Answer 2

Concept:

Spherical Mirrors.

Answer:

19 (i) The correct answer is option a) Outward Curve.

19 (ii) The correct answer is option a) Convex mirror.

         The part of the curve plate was acting like convex mirror.

19 (iii) The correct answer is option a) Virtual, erect and diminished.

            Convex mirror always  forms virtual, erect and diminished image.

19 (iv) The correct answer is option a) 20 cm.

         As the object is placed at a large distance from mirror, we consider that it is placed at infinity. When an object is at infinity in front of a convex mirror, then image is formed at focus.

So, distance of image = focal length = radius of curvature/2

    = 40/2 = 20 cm        [because radius of curvature = 40 cm (given)]

Hence, the image is formed at a distance of 20 cm.

19 (v) The correct answer is option a) Point size.

        Again we consider that the object is placed at infinity because the rays are parallel to principle axis. And it is placed in front of convex mirror. Convex mirror always forms diminished image.

Hence, the image will be point size and formed at focus.

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