A vessel is half filled with a liquid of refractive index μ. The other half of the vessel is filled with an immiscible liquid of refractive index 1.5 μ. The apparent depth of vessel is 50% of the actual depth. The value of μ is

A ray of red light is incident on the surface of a slab of glass at an angle of incidence of i. The angle of deviation in the slab is found to be ${\delta }_r$. When a ray of violet light is incident on the same slab of glass at same angle of incidence i, the angle of deviation inside the slab is found to be $\delta$. Then