If a wave gets refracted into a denser medium,then which of the following is true?

$A$ vessel of height $2d$ is half-filled with a liquid of refractive index $\sqrt{2}$ and the other half with a liquid of refractive index $n$ (the given liquids are immiscible). Then the apparent depth of the inner surface of the bottom of the vessel (neglecting the thickness of the bottom of the vessel) will be

For a colour of light,the wavelength in air is $6000 \ \mathring A$ and in water,the wavelength is $4500 \ \mathring A$. Then the speed of light in water will be:

The refractive index of water is $1.33$. What will be the speed of light in water?

Corpuscular theory of light predicts the speed of light to be

The wavelength of sodium light in air is $5890 \ \mathring{A}$. The velocity of light in air is $3 \times 10^8 \ m/s$. The wavelength of light in a glass of refractive index $1.6$ would be close to......$\mathring{A}$