Questions in Ray Optics and Optical Instruments

Select	Question
	An astronaut in a spaceship see the outer space as
	Speed of light is maximum in
	Which one of the following statements is correct
	If the wavelength of light in vacuum be $\lambda$, the wavelength in a medium of refractive index $n$ will be
	In vacuum the speed of light depends upon
	A transparent cube of 15 cm edge contains a small air bubble. Its apparent depth when viewed through one face is 6 cm and when viewed through the opposite face is 4 cm. Then the refractive index of the material of the cube is
	A glass slab of thickness 3 cm and refractive index 3/2 is placed on ink mark on a piece of paper. For a person looking at the mark at a distance 5.0 cm above it, the distance of the mark will appear to be
	A fish at a depth of 12 cm in water is viewed by an observer on the bank of a lake. To what height the image of the fish is raised.
	A cut diamond sparkles because of its
	A diver in a swimming pool wants to signal his distress to a person lying on the edge of the pool by flashing his water proof flash light