Question

06/04/2020
Physics
1) Due to which property of light does a stick in water look broken?
2) What is the bending of light around a very small object called?
3) If the angle of reflection is 60°, then what is the angle of incidence?
4) Which type of image can be obtained on a screen?
5) The reflecting surface of a spherical mirror is a part of a sphere. What is the centre of this sphere called?
6) What is the centre of the reflecting surface of a spherical mirror called?
7) What type of image is formed by a concave mirror if the object is placed beyond the centre of curvature?
8) The images formed by a plane mirror are always........
9) The kind of mirror most commonly used as the rear view mirror in vehicles
10) What is the speed of light?
11) The material that has the highest refractive index
12) What type of mirror is used by dentists to focus light on the teeth of the patient?
13) If the image formed by a concave mirror is real, inverted and of the same size as that of the object, then what is the position of the object?
14) A pencil when dipped in water in a glass tumbler appears to be bent at the interface of air and water. Will the pencil appear to be bent to the same extent, if instead of water we use liquids like kerosene or turpentine. Support your answer with reason.
15) Refractive index of diamond with respect to glass is 1•6 and absolute refractive index of glass is 1•5. Find the absolute refractive index of diamond.
16) A convex lens of focal length 20cm can produce a magnified, virtual as well as real image. Is this a correct statement? If yes, where shall the object be placed in each case for obtaining these images?
17) Draw ray diagrams showing the image formation by a concave mirror when an object is placed
A) between pole and focus of the mirror.
B) between focus and centre of curvature of the mirror.
C) at centre of curvature of the mirror
D) a little beyond centre of curvature of the mirror
E) at infinity​

Answer 1

Answer:

1. Due to the refraction of light stick looks broken in the water.
2. Bending of light around a very small object is called diffraction.
3. We know that angle i = angle r. so angle of incident ray is 60°
4. Real image can be obtained on a screen.
5. Centre of this sphere mirror is called centre of curvature.
6. Centre of the reflecting surface of a spherical mirror called Pole.
7. Real and inverted image is formed when object is placed beyond the centre of curvature in concave mirror.
8. The image formed by a plane mirror is always virtual upright, and of the same shape and size as the object.
9. Convex mirror is mostly used as rear view mirror in automobile.
10. Speed of light = 3 x 10^8 m/s
11. Silicon Carbide , Titanium dioxide , Diamond has the highest refractive index.
12. Concave mirror is used by dentist to focus light on the teeth of the patient.
13. If the image formed by a concave mirror is real, inverted and of the same size as that of the object, then position of objectvis at centre of curvature.
14. The refractive index changes object to object. Therefore, the pencil will not appear to be bent to the same extent, when it is dipped in kerosene or turpentine.
15. Absolute refractive index of diamond = Refractive in of diamond with respect to glass * Absolute refractive index of glass , nd = 1.5*1.6 = 2.4
16. Given statement is true. if object is placed between focus F1 and optical centre O ( less then 20 cm ).