Class 8
Dashboard
Science
Light: Mirrors and Lenses
NCERT Solutions
NCERT Solutions
Light: Mirrors and Lenses
12 Solutions
Q1
End-of-Chapter Questions
A light ray is incident on a mirror and gets reflected by it (Fig. 10.21). The angle made by the incident ray with the normal to the mirror is
40
∘
40^{\circ}
4
0
∘
. What is the angle made by the reflected ray with the mirror?
(i)
40
∘
40^{\circ}
4
0
∘
(ii)
50
∘
50^{\circ}
5
0
∘
(iii)
45
∘
45^{\circ}
4
5
∘
(iv)
60
∘
60^{\circ}
6
0
∘
Q2
End-of-Chapter Questions
Fig. 10.22 shows three different situations where a light ray falls on a mirror:
(i)
The light ray falls along the normal.
(ii)
The mirror is tilted, but the light ray still falls along the normal to the tilted surface.
(iii)
The mirror is tilted, and the light ray falls at an angle of
20
∘
20^{\circ}
2
0
∘
from the normal.
Draw the reflected ray in each case (Use a ruler and protractor for accurate drawing). What is the angle of reflection in each case?
Q3
End-of-Chapter Questions
In Fig. 10.23, the cap of a sketch pen is placed in front of three types of mirrors. Match each image with the correct mirror.
Image
Mirror
(i)
Plane mirror
(ii)
Convex mirror
(iii)
Concave mirror
Q4
End-of-Chapter Questions
In Fig. 10.24 the cap of a sketch pen is placed behind a convex lens, a concave lens, and a flat transparent glass piece - all at the same distance. Match each image with the correct type of lens or glass.
Image
Lens/glass type
(i)
Flat transparent glass piece
(ii)
Convex lens
(iii)
Concave lens
Q5
End-of-Chapter Questions
When the light is incident along the normal on the mirror, which of the following statements is true:
(i)
Angle of incidence is
90
∘
90^{\circ}
9
0
∘
(ii)
Angle of incidence is
0
∘
0^{\circ}
0
∘
(iii)
Angle of reflection is
90
∘
90^{\circ}
9
0
∘
(iv)
No reflection of light takes place in this case
Q6
End-of-Chapter Questions
Three mirrors-plane, concave and convex are placed in Fig. 10.25. On the basis of the images of the graph sheet formed in the mirrors, identify the mirrors and write their names above the mirrors.
Q7
End-of-Chapter Questions
In a museum, a woman walks towards a large convex mirror (Fig. 10.26). She will see that:
(i)
her erect image keeps decreasing in size.
(ii)
her inverted image keeps decreasing in size.
(iii)
her inverted image keeps increasing in size and eventually it becomes erect and magnified.
(iv)
her erect image keeps increasing in size.
Q8
End-of-Chapter Questions
Hold a magnifying glass over text and identify the distance where you can see the text bigger than they are written. Now move it away from the text. What do you notice? Which type of lens is a magnifying glass?
Q9
End-of-Chapter Questions
Match the entries in Column I with those in Column II.
| Column I | Column II |
|---|---|
| (i) Concave mirror | (a) Spherical mirror with a reflecting surface that curves inwards. |
| (ii) Convex mirror | (b) It forms an image which is always erect and diminished in size. |
| (iii) Convex lens | (c) Object placed behind it may appear inverted at some distance. |
| (iv) Concave lens | (d) Object placed behind it always appears diminished in size. |
Q10
End-of-Chapter Questions
The following question is based on Assertion/Reason.
Assertion: Convex mirrors are preferred for observing the traffic behind us.
Reason: Convex mirrors provide a significantly larger view area than plane mirrors. Choose the correct option:
(i)
Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.
(ii)
Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.
(iii)
Assertion is correct but Reason is incorrect.
(iv)
Both Assertion and Reason are incorrect.
Q11
End-of-Chapter Questions
In Fig. 10.27, note that O stands for object, M for mirror, and I for image. Which of the following statements is true?
(i)
Figure (a) indicates a plane mirror and Figure (b) indicates a concave mirror.
(ii)
Figure (a) indicates a convex mirror and Figure (b) indicates a concave mirror.
(iii)
Figure (a) indicates a concave mirror and Figure (b) indicates a convex mirror.
(iv)
Figure (a) indicates a plane mirror and Figure (b) indicates a convex mirror.
Q12
End-of-Chapter Questions
Place a pencil behind a transparent glass tumbler (Fig. 10.28a). Now fill the tumbler halfway with water (Fig. 10.28b). How does the pencil appear when viewed through the water? Explain why its shape appears changed.
More from this chapter
Chapter overview
Notes
Important Points
Practice Questions
Flashcards