Advertisements
Advertisements
Question
Explain the reason for glittering of diamond.
Solution
- The diamond appears dazzling because the total internal reflection of light happens inside the diamond.
- The refractive index of only diamonds is about 2.417. It is much larger than that for ordinary glass which is about only 1.5.
- The critical angle of a diamond is about 24.4°. It is much less than that of glass.
- A skilled diamond cutter makes use of this larger range of angle of incidence (24.4° to 90° inside the diamond), to ensure that light entering the diamond is total internally reflected from the many cut faces before getting out.
- This gives a sparkling effect for diamond.
APPEARS IN
RELATED QUESTIONS
Light incident normally on a plane mirror attached to a galvanometer coil retraces backward as shown in Figure. A current in the coil produces a deflection of 3.5° of the mirror. What is the displacement of the reflected spot of light on a screen placed 1.5 m away?
A narrow beam of light passes through a slab obliquely and is then received by an eye following figure. The index of refraction of the material in the slab fluctuates slowly with time. How will it appear to the eye? The twinkling of stars has a similar explanation.
A narrow beam of white light goes through a slab having parallel faces.
(a) The light never splits in different colours
(b) The emergent beam is white
(c) The light inside the slab is split into different colours
(d) The light inside the slab is white
The refractive index of a material changes by 0.014 as the colour of the light changes from red to violet. A rectangular slab of height 2.00 cm made of this material is placed on a newspaper. When viewed normally in yellow light, the letters appear 1.32 cm below the top surface of the slab. Calculate the dispersive power of the material.
A converging beam of light travelling in air converges at a point P as shown in the figure. When a glass sphere of refractive index 1 . 5 is introduced in between the path of the beam, calculate the new position of the image. Also draw the ray diagram for the image formed.
Why do stars twinkle?
What is looming?
When a light ray is incident on a prism at an angle of 45°, the minimum deviation is obtained. If refractive index of material of prism is `sqrt2`, then angle of prism will be ______.
`sin pi/4=1/sqrt2, sin30^circ=cos60^circ=1/2`
The critical angle is maximum when light travels from ______.
`(a^mu"w"=4/3,a^mug=3/2)`
A ray of unpolarised light is incident on the surface of glass plate of µ = 1.54 at polarising angle, then angle of refraction is
