Sparking Brilliance of Diamond:The total internal reflection of the light is used in polishing diamonds to create a sparking brilliance. By polishing the diamond with specific cuts, it is adjusted the most of the light rays approaching the surface are incident with an angle of incidence more than critical angle. Hence, they suffer multiple reflections and ultimately come out of diamond from the top. This gives the diamond a sparking brilliance. 1. Light cannot easily escape a diamond without multiple internal reflections. This is because: a) Its critical angle with reference to air is too large b) Its critical angle with reference to air is too small c) The diamond is transparent d) Rays always enter at angle greater than critical angle2. The critical angle for a diamond is 24.4o . Then its refractive index isa) 2.42 b) 0.413 c) 1 d) 1.413 3. The basic reason for the extraordinary sparkle of suitably cut diamond is that a) It has low refractive index b) It has high transparency c) It has high refractive index d) It is very hard 4. A diamond is immersed in a liquid with a refractive index greater than water. Then the critical angle for total internal reflection will a) will depend on the nature of the liquid b) decrease c) remains the same d) increase5. The following diagram shows same diamond cut in two different shapes.The brilliance of diamond in the second diamond will be: a) less than the first b) greater than first c) same as first d) will depend on the intensity of light