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