TEST 1 LIGHT 10TH APR 24 

TEST       PHYSICS: LIGHT     (UDAAN TUITION CENTER)               10TH APRIL’24

1.       Name a mirror that can give an erect and enlarged image of an object.                                                                [1 M]

2.   A concave mirror produces three times magnified (enlarged) real image of an object placed at 10 cm in front of it. Where is the image located?                                                                                                                                                     [1M]

3.       What happens when parallel rays of light are incident on a lens?                                                                         [1M]

4.       When a light falls on the lens the paper begins to burn producing smoke. It may even catch fire after a while. Why does this happen?                                                                                                                                                         [1M]

5.       Draw neat ray diagrams for the object placed between P and F of a Concave mirror. Labelled the Diagram [1M]

6.       An object, 4.0 cm in size, is placed at 25.0 cm in front of a concave mirror of focal length 15.0 cm. At what distance from the mirror should a screen be placed in order to obtain a sharp image? Find the nature and the size of the image.                                                                                                                                                                         [1M]

7.        

a.       Define power of a lens.

b.       What is its unit?

c.       One student uses a lens of focal length 50 cm and another of –50 cm. What is the nature of the lens and its power used by each of them?                                                                                                               [3M]

8.       A doctor has prescribed a corrective lens of power +1.5 D. Find the focal length of the lens. Is the prescribed lens diverging or converging?                                                                                                                                              [3M]

9.       Name the type of mirror used in the following situations. Support your answer with reason.

a.       Headlights of a car.

b.       Side/rear-view mirror of a vehicle

c.   Solar furnace

10.   How is the refractive index of a medium related to the speed of light? Obtain an expression for refractive index of a medium with respect to another in terms of speed of light in these two media?                                   [3M]

11.   Refractive index of X material with respect to glass is 1.6 and absolute refractive index of glass is 1.5. Find out the absolute refractive index of X.                                                                                                                                     [3M]

12.   How are power and focal length of a lens related? You are provided with two lenses of focal length 20 cm and 40 cm respectively. Which lens will you use to obtain more convergent light?                                                 [3M]

13.   Size of image of an object by a mirror having a focal length of 20 cm is observed to be reduced to (1/3)rd of its size. At what distance the object has been placed from the mirror? What is the nature of the image and the mirror?                                                                                                                                                                                   [3M]

14.   A student focussed the image of a candle flame on a white screen using a convex lens. He noted down the position of the candle screen and the lens as under

Position of candle  = 12.0 cm

Position of convex lens = 50.0 cm

Position of the screen = 88.0 cm

(i) Where will the image be formed if he shifts the candle towards the lens at a position of 31.0 cm?
(ii) What will be the nature of the image formed if he further shifts the candle towards the lens?
(iii) Draw a ray diagram to show the formation of the image in case as said above.                                     [4M]

15.) A spherical mirror and a thin spherical lens have each a focal length of –15cm. The mirror and the lens are likely to be  [1M]

a.   both concave.

b.  both convex.

c.   the mirror is concave and the lens is convex

d.  the mirror is convex, but the lens is concave

16. A full-length image of a distant tall building can definitely be seen by using [1M]

(a) a concave mirror
(b) a convex mirror
(c) a plane mirror
(d) both concave as well as plane mirror