Optical phenomena taking place for a mirror and a lens respectively are . . . . . . and . . . . . . .

According to the Cartesian sign convention in ray optics,

$A$ ray of light is incident on a medium of refractive index $\mu$ at an angle of incidence $i$. On refraction in the medium,$\delta$ is the angle of deviation. Then:

The refractive index of water in a biology laboratory tank varies as $1.33 + 0.002 / \lambda^2$,where $\lambda$ is the wavelength of light. Small pieces of organic matter of different colours are seen at the bottom of the tank using a travelling microscope. Then,the image of the organic matter appears

Blue light travelling in a vacuum has a wavelength of $450 \ nm$. It enters a medium whose refractive index is $1.5$. What is its frequency in the medium? $(Speed of light in vacuum = 3 \times 10^8 \ m \ s^{-1})$

As shown in the figure,after passing through medium $1$,the speed of light $v_{2}$ in medium $2$ will be $..... \times 10^{8} \, ms^{-1}$. (Given $c = 3 \times 10^{8} \, ms^{-1}$)