The refractive index of glass is 1.5 and that of water is 1.33 . The critical angle for a ray of light going from glass to water is

A convex lens is dipped in a liquid whose refractive index is equal to refractive index of lens material. Then its focal length will

A ray of light is incident at an angle 'I' on one face of thin prism. The ray emerges normally from the other face. Refractive index of the glass prism is '$$n$$' and angle of prism is '$$A$$'. The value of '$$\mathrm{I}$$' is

A glass cube of length $$24 \mathrm{~cm}$$ has a small air bubble trapped inside. When viewed normally from one face it is $$10 \mathrm{~cm}$$ below the surface. When viewed normally from the opposite face, its apparent distance is $$6 \mathrm{~cm}$$. The refractive index of glass is