Page 139 - Innovator's Science-8

iv. Her erect image keeps increasing in size.
Ans. The correct answer is (i) her erect image keeps decreasing in size. Because a convex mirror always forms
a virtual, erect, and diminished image.

8. Hold a magnifying glass over the text and iden fy the distance at which you can see the text bigger
than they are wri en. Now move it away from the text. What do you no ce? Which type of lens is a
magnifying glass?
Ans. A magnifying glass has a convex lens, which bends light rays to make objects look bigger. When you hold
it close to some text and slowly move it away, the way the lens bends light changes the image you see. At
first, the text looks bigger and clearer because the lens is focusing the light well. As you keep moving the
glass farther, the text s ll appears bigger but starts to get blurry because the focus point moves away
from your eyes. If you move it even farther, the image flips upside down and looks smaller again because
the light rays cross over and form what’s called an inverted real image.

9. Match the entries in Column I with those in Column II.

Column I Column I
i. Concave mirror a. Spherical mirror with a reflec ng 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.

Ans. Column I Column I

i. Concave mirror a. Spherical mirror with a reflec ng surface that curves inwards.
ii. Convex mirror b. It forms an image which is always erect and diminished in size.
iii. Convex lens c. An object placed behind it may appear inverted at some distance.
iv. Concave lens d. The object placed behind it always appears diminished in size.

10. The following ques on is based on Asser on/Reason.
Asser on: 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 op on:
i. Both Asser on and Reason are correct, and Reason is the correct explana on for Asser on.
ii. Both Asser on and Reason are correct, but Reason is not the correct explana on for Asser on.
iii. Asser on is correct, but Reason is incorrect.
iv. Both Asser on and Reason are incorrect.
Ans. (i) Both Asser on and Reason are correct, and Reason is the correct explana on for Asser on.

11. In the Figure, note that O stands for object, M for mirror, and I for image.

O M I
a.

O M I
b.
Which of the following statements is true?
i. Figure (a) indicates a plane mirror, and Figure (b) indicates a concave mirror.

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