WORK SHEET OF REFLECTION

Class 10 - Science
Time Allowed: 2 hours Maximum Marks: 138

Section A
1. Read the text carefully and answer the questions:
Hold a concave mirror in your hand and direct its reflecting surface towards the sun. Direct the light reflected by the
mirror on to a white card-board held close to the mirror. Move the card-board back and forth gradually until you find
a bright, sharp spot of light on the board. This spot of light is the image of the sun on the sheet of paper; which is also
termed as Principal Focus of the concave mirror.

(a) List two applications of concave mirror.

(b) If the distance between the mirror and the principal focus is 15 cm, find the radius of curvature of the mirror.
(c) Draw a ray diagram to show the type of image formed when an object is placed between pole and focus of a
concave mirror.
(d) An object 10 cm in size is placed at 100 cm in front of a concave mirror. If its image is formed at the same
point where the object is located, find:
i. focal length of the mirror, and
ii. magnification of the image formed with sign as per Cartesian sign convention.
2. Read the text carefully and answer the questions:
A student took three concave mirrors of different focal lengths and performed the experiment to see the image
formation by placing an object at different distances with these mirrors as shown in the following table.

Case No. Object-distance Focal length

I 45 cm 20 cm

II 30 cm 15 cm

III 20 cm 30 cm

(a) List two properties of the image formed in Case I.

(b) In which one of the cases given in the table, the mirror will form real image of same and why?
(c) Name the type of mirror used by dentists. Give reason why do they use such type of mirrors.
(d) Look at the table and identify the situation (object distance and focal length) which resembles the situation in
which concave mirrors are used as shaving mirrors? Draw a ray diagram to show the image formation in this
case.

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 Section B
3. Plane and convex mirrors produce virtual images of objects. Can they produce real images under some circumstances?
Explain.
4. A man stands in front of a mirror of Special shape. He finds that his image has a very small head, a fat body, and legs of
normal size. What can we say about the shapes of three parts of the mirror?
5. Will the reflected rays converge at a point when a parallel beam of light is incident on a concave mirror of large
aperture?
6. Why is a concave mirror preferred to a plane mirror for Shaving?
7. You read a newspaper because of the light that it reflects. Then why do you not see even a faint image of yourself in the
newspaper?
Section C
8. Assertion (A): A plane mirror may form a real image.
Reason (R): Plane mirror forms a virtual image if the object is real.

a) Both A and R are true and R is the correct b) Both A and R are true but R is not the
explanation of A. correct explanation of A.

c) A is true but R is false. d) A is false but R is true.

9. Assertion (A): A virtual image cannot be photographed.
Reason (R): Only real objects are photographed.

a) Both A and R are true and R is the correct b) Both A and R are true but R is not the
explanation of A. correct explanation of A.

c) A is true but R is false. d) A is false but R is true.

10. Assertion (A): When the object moves with a velocity of 2 m/s, its image in the plane mirror moves with the velocity of
4m/s.
Reason (R): The image formed by the plane mirror is as far behind the mirror as the object is in front of it.

a) Both A and R are true and R is the correct b) Both A and R are true but R is not the
explanation of the assertion. correct explanation of A.

c) A is true but R is false. d) A is false but R is true.

11. Assertion (A): The nature of the image formed by a concave mirror is real and inverted.
Reason (R): The image formed by a concave mirror depends on the position of the object at infinity.

a) Both A and R are true and R is the correct b) Both A and R are true but R is not the
explanation of A. correct explanation of A.

c) A is true but R is false. d) A is false but R is true.

12. Assertion (A): It is impossible to see a virtual image.
Reason (R): The rays that seen to emanate from a virtual image don't, in fact, emanates from the image.

a) Both A and R are true and R is the correct b) Both A and R are true but R is not the
explanation of the assertion. correct explanation of A.

c) A is true but R is false. d) A is false but R is true.

13. Assertion (A): The height of an object is always considered positive.
Reason (R): An object is always placed above the principal axis in the upward direction.

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 a) Both A and R are true and R is the correct b) Both A and R are true but R is not the
explanation of the assertion. correct explanation of A.

c) A is true but R is false. d) A is false but R is true.

14. Assertion (A): The mirrors used in searchlights are concave spherical.
Reason (R): In the concave spherical mirror the image formed is always virtual.

a) Both A and R are true and R is the correct b) Both A and R are true but R is not the
explanation of the assertion. correct explanation of A.

c) A is true but R is false. d) A is false but R is true.

15. Assertion (A): If a ray of light is incident on a convex mirror along its principal axis, then the angle of incidence, as well
as the angle of reflection for a ray of light, will be zero.
Reason (R): A ray of light going towards the centre of curvature of a convex mirror is reflected back along the same
path.

a) Both A and R are true and R is the correct b) Both A and R are true but R is not the
explanation of A. correct explanation of A.

c) A is true but R is false. d) A is false but R is true.

16. Assertion (A): Large concave mirrors are used to concentrate sunlight to produce heat in solar cookers.
Reason (R): Concave mirror converges the light rays falling on it to a point.

a) Both A and R are true and R is the correct b) Both A and R are true but R is not the
explanation of A. correct explanation of A.

c) A is true but R is false. d) A is false but R is true.

17. Assertion (A): A convex mirror is used as a driver's mirror.
Reason (R): Because convex mirror's field of view is large and images formed are virtual, erect and diminished.

a) Both A and R are true and R is the correct b) Both A and R are true but R is not the
explanation of A. correct explanation of A.

c) A is true but R is false. d) A is false but R is true.

Section D
18. On regular reflection from the surface XY, the reflected ray will go along:

a) A b) D

c) B d) C
19. Four students A, B, C, and D carried out measurement of the focal length of a concave mirror as shown in the following
four diagrams.

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 The best result will be obtained by the student:

a) A b) B

c) D d) C
20. A student determines the focal length of a device X, by focusing the image of a far off object on the screen positioned as
shown in the figure below:

The device X is a :

a) Convex mirror b) Concave mirror

c) Concave lens d) Convex lens

21. The figure given alongside shows the image of a clock as seen in a plane mirror. The correct time is:

a) 2.35 b) 9.25

c) 2.25 d) 6.45
22. Which of the following ray diagrams is correct for the ray of light incident on a concave mirror as shown in the figure?

a) b)

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 c) d)

Section E
23. Why are concave mirrors used in a solar furnace?
24. Should the mirror always be made of glass ?
25. What are the values of (i) Angle of incidence and (ii) Angle of reflection for normal incidence on a plane surface?
26. In what way is the word AMBULANCE printed in front of the hospital vans? Why is it printed this way?
27. If an object is held at a distance of 60 cm from a convex mirror of focal length 20 cm. At what distance from the convex
mirror, should a plane mirror be held, so that images in the two mirrors coincide?
28. Draw ray diagram showing the image formation by a concave mirror when an object placed between pole and focus of
the mirror.
29. Size of image of an object by a mirror having a focal length of 20cm is observed to be reduced to 1/3rd of its size. At
what distance the object has been placed from the mirror? What is the nature of the image and the mirror?
30. Name a mirror which can give an erect and enlarged image of an object.
31. Draw ray diagram showing the image formation by a concave mirror when an object placed a little beyond centre of
curvature of the mirror.
32. A 4 cm tall object is placed on the principal axis of convex lens. The distance of the object from the optical centre of the
lens is 12 cm and its sharp image is formed at a distance of 24 cm from it on a screen on the other side of the lens. If the
object is now moved a little away from the lens, in which way (towards the lens or away from the lens) will he have to
move the screen to get a sharp image of the object on it again? How will the magnification of the image be affected?
33. Draw ray diagram to show the principal focus of a:
a. Concave Mirror
b. Convex Mirror
34. An object is kept at a distance of 15cm from a
i. convex mirror
ii. concave lens
iii. Plane mirror.
The focal length of the convex mirror and the concave lens are 10 cm each.
Draw the appropriate ray diagrams, showing the formation of image, in each of the three cases.
35. A concave mirror produces three times magnified (enlarged) real image of an object 10 cm in front of it. Where is the
image located?
36. Why do we prefer a convex mirror as a rear-view mirror in vehicles?
37. An object is placed at a distance of 10 cm from a convex mirror of focal length 15 cm. Find the position and nature of
the image.

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38. i. What should be the position of the object when a concave mirror is to be used
a. as a shaving mirror and
b. in torches producing parallel beam of light?
ii. A man standing in front of a mirror, finds his image having a very small head and legs of normal size. What type of
mirrors are used in designing such a mirror?
39. A student wants to project the image of a candle flame on a screen 80 cm in front of a mirror by keeping the candle
flame at a distance of 20 m from its pole.
i. Which type of mirror should the student use?
ii. Find the magnificent of the image produced.
iii. Find the distance between the object and its image.
40. Distinguish between real image and virtual image.
41. "A concave mirror of focal length f can form a magnified, erect as well as an inverted image of an object placed in front
of it." Justify this statement stating the position of object with respect to the mirror in each case for obtaining these
images.
42. How can you distinguish between plane mirror, convex mirror and concave mirror by merely looking at the image
formed in each case?
43. Under what condition in an arrangement of two plane mirrors, incident ray and reflected ray will always be parallel to
each other, whatever may be angle of incidence. Show the same with the help of diagram.
44. An object 2 cm high is placed at a distance of 16 cm from a concave mirror which produce a real image 3 cm high.
(i) What is the focal length of the mirror ?
(ii) Find the position of the image.
45. We wish to obtain an erect image of an object, using a concave mirror of focal length 15 cm. What should be the range of
distance of the object from the mirror? What is the nature of the image? Is the image larger or smaller than the object?
Draw a ray diagram to show the image formation in this case.
46. An object 2 cm high is placed at a distance of 16 cm from a concave mirror which produces a real image 3 cm high.
(i)Find the position of the image.
(ii)What is the focal length of mirror?
47. Define magnification of a spherical mirror. What will be the magnification in case of plane mirror?
48. Define the principal focus of concave mirror.
49. a. List four characteristics of the images formed by plane mirrors.
b. A 5 cm tall object is placed at a distance of 20 cm from a concave mirror of focal length 30 cm. Use mirror formula
to determine the position and size of the image formed.
50. An object 5 cm high is placed at a distance of 10 cm from a convex mirror of radius of curvature 30 cm. Find the nature,
position and size of the image.
51. A student places a candle flame at a distance of about 60 cm from a convex lens of focal length 10 cm and focuses the
image of the flame on a screen. After that he gradually moves the flame towards the lens and each time focuses the
image on the screen.
i. In which direction: toward or away from the lens, does he move the screen to focus the image?
ii. How does the size of the image change?
iii. How does the intensity of the image change as the flame moves towards the lens?
iv. Approximately for what distance between the flame and the lens, the image formed on the screen is inverted and of
the same size?

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52. What are rules for formation of images?
53. An object 4.0 cm in size, is placed 25.0 cm in front of a concave mirror of focal length 15.0 cm.
i. At what distance from the mirror should a screen be placed in order to obtain a sharp image?
ii. Find the size of the image.
iii. Draw a ray diagram to show the formation of image in this case.
54. Differentiate between a concave mirror and a convex mirror.

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