A piece of glass is not visible in a colourless transparent liquid. It is possible because

Options

A. both the materials have same density
B. both the materials are colourless
C. both the materials have same refractive index
D. light moves with different speed in the two mediums involved

Answer

C

Explanation

If materials have same refractive index then due to no change in path of ray it becomes hard to distinguish. Along with the same refractive index, glass slab should not appreciably reflect the light to remain completely invisible inside the liquid.