When light enters glass from vacuum,then the wavelength of light:

Monochromatic light of frequency $5 \times 10^{14} \ Hz$ travelling in vacuum enters a medium of refractive index $1.5$. Its wavelength in the medium is ....... $\mathring{A}$.

The refractive index of water with respect to air is $4/3$ and the refractive index of glass with respect to air is $3/2$. The refractive index of water with respect to glass is

The refractive indices of water and glass with respect to air are $1.2$ and $1.5$ respectively. The refractive index of glass with respect to water is

$A$ fish rising vertically up towards the surface of water with speed $3 \; ms^{-1}$ observes a bird diving vertically down towards it with speed $9 \; ms^{-1}$. The actual velocity of the bird is.......$ms^{-1}$ (Assume refractive index of water $\mu = 4/3$).

When light enters glass from vacuum,then the wavelength of light